Gerber Viewer for GitHub

Tracking since May 9, 2026.

Changelog

• May 25, 2026
  description

  Preview PCB design files inline while browsing GitHub. No more downloading
  Gerber archives, unzipping them, and opening a separate tool just to see what
  a board looks like.
  
  Gerber Viewer for GitHub adds an interactive preview panel above the regular
  file view whenever you open a Gerber, Excellon drill, ZIP archive, or KiCad
  file in a public or private repository. It works in four places:
  
  * On a single-file blob page (e.g. /blob/main/board.gtl), it renders the layer
    immediately, then fetches sibling files in the same folder to build a
    realistic Top and Bottom composite view with copper, soldermask, silkscreen,
    and drill holes.
  
  * On a folder page (e.g. /tree/main/gerbers/), it detects layer-set folders
    automatically and shows the same composite view without needing to open an
    individual file first.
  
  * On a ZIP archive committed to a repo, it downloads and extracts the archive
    entirely in your browser, finds the Gerber files inside, and builds the
    same multi-layer preview.
  
  * On a GitHub Gist that contains Gerber files, it does the same as the blob
    and folder cases, using the Gist API to fetch file content inline.
  
  For KiCad .kicad_pcb board files and .kicad_sch schematic files, the extension
  embeds the KiCanvas viewer directly in the page, giving you full layer toggles,
  zoom, and pan over the native KiCad format.
  
  ----------------------------------------
  What's in the toolbar
  ----------------------------------------
  
  Layer / Top / In1 / In2 / ... / Bottom tabs to switch between views. Inner
  copper tabs appear automatically for multi-layer boards.
  
  Zoom controls with mouse-wheel zoom-to-cursor, step buttons, and Fit.
  
  Click-and-drag panning.
  
  Two rotation buttons for 90 degree steps.
  
  Chain measurement tool. Click two or more points to measure distances in mm
  or mil, with running totals shown in the status bar. Backspace undoes the
  last point, Escape exits.
  
  Layers menu for hiding silkscreen, soldermask, solderpaste, copper, substrate,
  or board outline independently. Useful for design reviews where you want to
  inspect routing without silkscreen clutter. The hidden state persists across
  Top / Bottom switches.
  
  Outline toggle for boards whose .gko / Edge_Cuts file has disconnected
  segments, fab markings, or fiducials mixed into the boundary geometry. Flips
  between using the outline file and computing the boundary from the union of
  features.
  
  Invert (dark mode) for the rendered board.
  
  Download SVG of the current view at the current zoom.
  
  Hide / Show to collapse the panel without losing state.
  
  ----------------------------------------
  Bill of materials extraction
  ----------------------------------------
  
  When a folder, ZIP archive, or Gist contains a bom.csv, bom.tsv, bom.xlsx, or
  bom.xls file alongside the Gerber files, the extension parses it and shows
  the rows in a sortable table below the board preview. CSV parsing is built
  in; Excel parsing uses a bundled copy of SheetJS that loads lazily on the
  first BOM encountered. Multi-sheet Excel workbooks get a sheet picker, with
  the sheet named "BOM" or "Bill of Materials" selected by default. Numeric
  and date cells are coerced to their display values so a date column reads as
  "2024-03-15" rather than as Excel's serial number 45366. A Copy as TSV button
  copies the current view to your clipboard in a spreadsheet-friendly format.
  
  ----------------------------------------
  Keyboard shortcuts
  ----------------------------------------
  
  Z fits the view, R rotates clockwise (Shift+R counter-clockwise), M toggles
  the measurement tool, U toggles between mm and mil, L / T / B switch to
  Layer / Top / Bottom views, O toggles the outline file, I inverts the theme,
  H hides the panel, and ? opens a help overlay listing every shortcut along
  with a note on how the measurement tool works.
  
  ----------------------------------------
  Gerber X2 and X3 attribute support
  ----------------------------------------
  
  When a Gerber file declares its role via %TF.FileFunction*%,
  %TF.GenerationSoftware*%, or related X2/X3 attributes, the preview header
  shows that information directly. So instead of guessing "is this top copper or
  bottom?" from a cryptic .gtl filename, you see "Top copper (L1) - KiCad 7.0.5"
  in the toolbar.
  
  ----------------------------------------
  Settings page
  ----------------------------------------
  
  Open via the Extensions menu (puzzle-piece icon) -> three-dot menu -> Options.
  Toggle the default measurement unit (mm or mil), default theme (light or
  dark), default outline mode, default panel collapsed state, and an optional
  cap on GitHub API calls per page. Settings persist across browser sessions.
  
  The Settings page also has a Copy Diagnostics button that writes a JSON blob
  to your clipboard with the extension version, your browser's user-agent, and
  the most recent 50 events (activations, file loads, errors). Useful for bug
  reports. The blob is purely local; nothing is sent anywhere.
  
  ----------------------------------------
  Privacy and security
  ----------------------------------------
  
  All parsing and rendering happens client-side, in your browser, on your
  machine. The extension does not send file contents to any server, ever. It
  does not collect telemetry. It does not run remote code. The only network
  requests it makes are to raw.githubusercontent.com and api.github.com (to
  fetch the files and folder listings you're viewing on GitHub), plus
  gist.githubusercontent.com when you're on a Gist page.
  
  The KiCanvas, SheetJS, tracespace, and fflate libraries are bundled inside
  the extension and loaded from the extension's own resources, not from any
  third-party CDN.
  
  Full privacy policy at the URL provided on the listing page.
  
  ----------------------------------------
  Built on tracespace, KiCanvas, fflate, and SheetJS
  ----------------------------------------
  
  The Gerber rendering pipeline is powered by the tracespace v4 toolkit
  (gerber-to-svg, pcb-stackup, whats-that-gerber) which is the same library set
  used by major online PCB review tools. ZIP support uses fflate. KiCad
  rendering uses KiCanvas. Excel BOM parsing uses SheetJS Community Edition. All
  five libraries are bundled directly into the extension; no remote code is
  fetched at runtime.
  
  ----------------------------------------
  Open source
  ----------------------------------------
  
  GPL-3.0 licensed. Source available at
  github.com/GreenShoeGarage/GitHub_GerberViewer_ChromeExtension. Bug reports
  and feature suggestions welcome.
  
  ----------------------------------------
  What's new in v0.9.3
  ----------------------------------------
  
  * Excel BOM support (.xlsx and .xls) via lazy-loaded SheetJS
  * Sheet picker for multi-sheet workbooks
  
  Recent versions (v0.9.x line):
  
  * v0.9.2: KiCad schematic (.kicad_sch) support, GitHub Gist support, keyboard
    shortcuts and help overlay, CSV BOM extraction, stackup layer visibility
    toggles
  * v0.9.1: Updated project URLs and homepage link
  * v0.9.0: Structured error handling with actionable suggestions, settings
    page, copy-diagnostics button

  Preview PCB design files inline while browsing GitHub. No more downloading
  Gerber archives, unzipping them, and opening a separate tool just to see what
  a board looks like.
   
  Gerber Viewer for GitHub adds an interactive preview panel above the regular
  file view whenever you open a Gerber, Excellon drill, ZIP archive, or KiCad
  file in a public or private repository. It works in five places, plus pull requests:
   
  * On a single-file blob page (e.g. /blob/main/board.gtl), it renders the layer
    immediately, then fetches sibling files in the same folder to build a
    realistic Top and Bottom composite view with copper, soldermask, silkscreen,
    and drill holes.
   
  * On a folder page (e.g. /tree/main/gerbers/), it detects layer-set folders
    automatically and shows the same composite view without needing to open an
    individual file first.
   
  * On a ZIP archive committed to a repo, it downloads and extracts the archive
    entirely in your browser, finds the Gerber files inside, and builds the
    same multi-layer preview.
   
  * On a GitHub Gist that contains Gerber files, it does the same as the blob
    and folder cases, using the Gist API to fetch file content inline.
   
  * On a pull request's "Files changed" tab, it finds the Gerber, drill, and
    KiCad files the pull request touches and renders a before/after preview for
    each one, so you can see what a board change looks like without checking out
    the branch. Added files show the new board, removed files show the old one,
    and modified files show both side by side.
   
  For KiCad .kicad_pcb board files and .kicad_sch schematic files, the extension
  embeds the KiCanvas viewer directly in the page, giving you full layer toggles,
  zoom, and pan over the native KiCad format.
   
  ----------------------------------------
  What's in the toolbar
  ----------------------------------------
   
  Layer / Top / In1 / In2 / ... / Bottom tabs to switch between views. Inner
  copper tabs appear automatically for multi-layer boards.
   
  Zoom controls with zoom-to-cursor, step buttons, and Fit. Plain scrolling
  passes through to the page so you can scroll past the board normally. To
  zoom, pinch on a trackpad, or hold Cmd (Ctrl on Windows and Linux) while
  scrolling.
   
  Click-and-drag panning.
   
  Two rotation buttons for 90 degree steps.
   
  Measurement tool. Click a start point, then an end point, to measure the
  distance in mm or mil. The measurement locks when you finish, so it does not
  auto-start a new line. Click again to measure something else, or Shift-click
  to extend the current measurement into a multi-segment chain with a running
  total. Backspace undoes the last point, Escape exits.
   
  Layers menu for hiding silkscreen, soldermask, solderpaste, copper, substrate,
  or board outline independently. Useful for design reviews where you want to
  inspect routing without silkscreen clutter. The hidden state persists across
  Top / Bottom switches.
   
  Color menu for rendering the board in green, red, blue, black, white, yellow,
  or purple soldermask, so the preview can match the board you actually ordered.
  Dark colors automatically pair with white silkscreen and light colors with
  black silkscreen so the legend stays readable. A default color can be set in
  the settings page.
   
  Outline toggle for boards whose .gko / Edge_Cuts file has disconnected
  segments, fab markings, or fiducials mixed into the boundary geometry. Flips
  between using the outline file and computing the boundary from the union of
  features.
   
  Invert (dark mode) for the rendered board.
   
  Download SVG of the current view at the current zoom.
   
  Hide / Show to collapse the panel without losing state.
   
  ----------------------------------------
  Bill of materials extraction
  ----------------------------------------
   
  When a folder, ZIP archive, or Gist contains a bom.csv, bom.tsv, bom.xlsx, or
  bom.xls file alongside the Gerber files, the extension parses it and shows
  the rows in a sortable table below the board preview. CSV parsing is built
  in; Excel parsing uses a bundled copy of SheetJS that loads lazily on the
  first BOM encountered. Multi-sheet Excel workbooks get a sheet picker, with
  the sheet named "BOM" or "Bill of Materials" selected by default. Numeric
  and date cells are coerced to their display values so a date column reads as
  "2024-03-15" rather than as Excel's serial number 45366. A Copy as TSV button
  copies the current view to your clipboard in a spreadsheet-friendly format.
   
  ----------------------------------------
  Keyboard shortcuts
  ----------------------------------------
   
  Z fits the view, R rotates clockwise (Shift+R counter-clockwise), M toggles
  the measurement tool, U toggles between mm and mil, L / T / B switch to
  Layer / Top / Bottom views, O toggles the outline file, I inverts the theme,
  H hides the panel, and ? opens a help overlay listing every shortcut along
  with a note on how the measurement tool works.
   
  ----------------------------------------
  Gerber X2 and X3 attribute support
  ----------------------------------------
   
  When a Gerber file declares its role via %TF.FileFunction*%,
  %TF.GenerationSoftware*%, or related X2/X3 attributes, the preview header
  shows that information directly. So instead of guessing "is this top copper or
  bottom?" from a cryptic .gtl filename, you see "Top copper (L1) - KiCad 7.0.5"
  in the toolbar.
   
  ----------------------------------------
  Settings page
  ----------------------------------------
   
  Open via the Extensions menu (puzzle-piece icon) -> three-dot menu -> Options.
  Toggle the default measurement unit (mm or mil), default theme (light or
  dark), default outline mode, default board color, default panel collapsed
  state, and an optional cap on GitHub API calls per page. Settings persist
  across browser sessions.
   
  The Settings page also has a Copy Diagnostics button that writes a JSON blob
  to your clipboard with the extension version, your browser's user-agent, and
  the most recent 50 events (activations, file loads, errors). Useful for bug
  reports. The blob is purely local; nothing is sent anywhere.
   
  ----------------------------------------
  Privacy and security
  ----------------------------------------
   
  All parsing and rendering happens client-side, in your browser, on your
  machine. The extension does not send file contents to any server, ever. It
  does not collect telemetry. It does not run remote code. The only network
  requests it makes are to raw.githubusercontent.com and api.github.com (to
  fetch the files and folder listings you're viewing on GitHub), plus
  gist.githubusercontent.com when you're on a Gist page.
   
  The KiCanvas, SheetJS, tracespace, and fflate libraries are bundled inside
  the extension and loaded from the extension's own resources, not from any
  third-party CDN.
   
  Full privacy policy at the URL provided on the listing page.
   
  ----------------------------------------
  Built on tracespace, KiCanvas, fflate, and SheetJS
  ----------------------------------------
   
  The Gerber rendering pipeline is powered by the tracespace v4 toolkit
  (gerber-to-svg, pcb-stackup, whats-that-gerber) which is the same library set
  used by major online PCB review tools. ZIP support uses fflate. KiCad
  rendering uses KiCanvas. Excel BOM parsing uses SheetJS Community Edition. All
  five libraries are bundled directly into the extension; no remote code is
  fetched at runtime.
   
  ----------------------------------------
  Open source
  ----------------------------------------
   
  GPL-3.0 licensed. Source available at
  github.com/GreenShoeGarage/GitHub_GerberViewer_ChromeExtension. Bug reports
  and feature suggestions welcome.
   
  ----------------------------------------
  What's new in v1.0.0
  ----------------------------------------
   
  * Pull request support: a before/after preview of every Gerber, drill, and
    KiCad file changed in a pull request, right on the "Files changed" tab.
  * Hardening for everyday use: continuous integration runs the full test
    suite and a bundle-size budget on every change, the panel-insertion logic
    is more resilient to GitHub layout changes, and a corpus of awkward
    real-world boards is now part of the test suite.
   
  Recent versions:
   
  * v0.9.5: Board color control (green, red, blue, black, white, yellow,
    purple soldermask) with auto-paired silkscreen
  * v0.9.4: Two-click measurement tool (Shift-click to chain), and zoom that no
    longer hijacks page scrolling (pinch or Cmd/Ctrl-scroll to zoom)
  * v0.9.3: Excel BOM support (.xlsx and .xls) via lazy-loaded SheetJS, with a
    sheet picker for multi-sheet workbooks
  * v0.9.2: KiCad schematic (.kicad_sch) support, GitHub Gist support, keyboard
    shortcuts and help overlay, CSV BOM extraction, stackup layer visibility
    toggles
  * v0.9.1: Updated project URLs and homepage link
  * v0.9.0: Structured error handling with actionable suggestions, settings
    page, copy-diagnostics button

• May 19, 2026
  description

  Preview PCB design files inline while browsing GitHub. No more downloading Gerber archives, unzipping them, and opening a separate tool just to see what a board looks like.
   
  Gerber Viewer for GitHub adds an interactive preview panel above the regular file view whenever you open a Gerber, Excellon drill, ZIP archive, or KiCad PCB file in a public or private repository. It works in three places:
   
  * On a single-file blob page (e.g. /blob/main/board.gtl), it renders the layer   immediately, then fetches sibling files in the same folder to build a realistic Top and Bottom composite view with copper, soldermask, silkscreen, and drill holes.
   
  * On a folder page (e.g. /tree/main/gerbers/), it detects layer-set folders automatically and shows the same composite view without needing to open an individual file first.
   
  * On a ZIP archive committed to a repo, it downloads and extracts the archive entirely in your browser, finds the Gerber files inside, and builds the same multi-layer preview.
   
  For KiCad .kicad_pcb files, the extension embeds the KiCanvas board viewer directly in the page, giving you full layer toggles, zoom, and pan over the native KiCad format.
   
  ----------------------------------------
  What's in the toolbar
  ----------------------------------------
   
  Layer / Top / In1 / In2 / ... / Bottom tabs to switch between views. Inner
  copper tabs appear automatically for multi-layer boards.
   
  Zoom controls with mouse-wheel zoom-to-cursor, step buttons, and Fit.
   
  Click-and-drag panning.
   
  Two rotation buttons for 90 degree steps.
   
  Chain measurement tool. Click two or more points to measure distances in mm
  or mil, with running totals shown in the status bar. Backspace undoes the
  last point, Escape exits.
   
  Outline toggle for boards whose .gko / Edge_Cuts file has disconnected
  segments, fab markings, or fiducials mixed into the boundary geometry. Flips
  between using the outline file and computing the boundary from the union of
  features.
   
  Invert (dark mode) for the rendered board.
   
  Download SVG of the current view at the current zoom.
   
  Hide / Show to collapse the panel without losing state.
   
  ----------------------------------------
  Gerber X2 and X3 attribute support
  ----------------------------------------
   
  When a Gerber file declares its role via %TF.FileFunction*%,
  %TF.GenerationSoftware*%, or related X2/X3 attributes, the preview header
  shows that information directly. So instead of guessing "is this top copper or
  bottom?" from a cryptic .gtl filename, you see "Top copper (L1) • KiCad 7.0.5"
  in the toolbar.
   
  ----------------------------------------
  Privacy and security
  ----------------------------------------
   
  All parsing and rendering happens client-side, in your browser, on your
  machine. The extension does not send file contents to any server, ever. It
  does not collect telemetry. It does not run remote code. The only network
  requests it makes are to raw.githubusercontent.com (to fetch the Gerber and
  drill files you're viewing) and api.github.com (to list the contents of the
  folder you're in).
   
  For .kicad_pcb files, the KiCanvas library is bundled inside the extension
  and loaded from the extension's own resources, not from any third-party CDN.
   
  ----------------------------------------
  Built on tracespace and KiCanvas
  ----------------------------------------
   
  The Gerber rendering pipeline is powered by the tracespace v4 toolkit
  (gerber-to-svg, pcb-stackup, whats-that-gerber) which is the same library set
  used by major online PCB review tools. ZIP support uses fflate. KiCad
  rendering uses KiCanvas. All five libraries are bundled directly into the
  extension; no remote code is fetched at runtime.
   
  ----------------------------------------
  Open source
  ----------------------------------------
   
  GPL-3.0 licensed. Source available at the project repository (see Website
  link below). Bug reports and feature suggestions welcome.
   
  ----------------------------------------
  What's new in v0.8.1
  ----------------------------------------
   
  * KiCad .kicad_pcb file support via the bundled KiCanvas library
  * Graceful fallback for systems where WebGL2 is unavailable, with file
    metadata and a raw-file download link
  * Inner copper layer browsing for 4+ layer boards (In1, In2, ... tabs)
  * Chain measurement mode with running totals and undo
  * Gerber X2 / X3 attribute parsing in the panel header
   
  Made by Green Shoe Garage.

  Preview PCB design files inline while browsing GitHub. No more downloading
  Gerber archives, unzipping them, and opening a separate tool just to see what
  a board looks like.
  
  Gerber Viewer for GitHub adds an interactive preview panel above the regular
  file view whenever you open a Gerber, Excellon drill, ZIP archive, or KiCad
  file in a public or private repository. It works in four places:
  
  * On a single-file blob page (e.g. /blob/main/board.gtl), it renders the layer
    immediately, then fetches sibling files in the same folder to build a
    realistic Top and Bottom composite view with copper, soldermask, silkscreen,
    and drill holes.
  
  * On a folder page (e.g. /tree/main/gerbers/), it detects layer-set folders
    automatically and shows the same composite view without needing to open an
    individual file first.
  
  * On a ZIP archive committed to a repo, it downloads and extracts the archive
    entirely in your browser, finds the Gerber files inside, and builds the
    same multi-layer preview.
  
  * On a GitHub Gist that contains Gerber files, it does the same as the blob
    and folder cases, using the Gist API to fetch file content inline.
  
  For KiCad .kicad_pcb board files and .kicad_sch schematic files, the extension
  embeds the KiCanvas viewer directly in the page, giving you full layer toggles,
  zoom, and pan over the native KiCad format.
  
  ----------------------------------------
  What's in the toolbar
  ----------------------------------------
  
  Layer / Top / In1 / In2 / ... / Bottom tabs to switch between views. Inner
  copper tabs appear automatically for multi-layer boards.
  
  Zoom controls with mouse-wheel zoom-to-cursor, step buttons, and Fit.
  
  Click-and-drag panning.
  
  Two rotation buttons for 90 degree steps.
  
  Chain measurement tool. Click two or more points to measure distances in mm
  or mil, with running totals shown in the status bar. Backspace undoes the
  last point, Escape exits.
  
  Layers menu for hiding silkscreen, soldermask, solderpaste, copper, substrate,
  or board outline independently. Useful for design reviews where you want to
  inspect routing without silkscreen clutter. The hidden state persists across
  Top / Bottom switches.
  
  Outline toggle for boards whose .gko / Edge_Cuts file has disconnected
  segments, fab markings, or fiducials mixed into the boundary geometry. Flips
  between using the outline file and computing the boundary from the union of
  features.
  
  Invert (dark mode) for the rendered board.
  
  Download SVG of the current view at the current zoom.
  
  Hide / Show to collapse the panel without losing state.
  
  ----------------------------------------
  Bill of materials extraction
  ----------------------------------------
  
  When a folder, ZIP archive, or Gist contains a bom.csv, bom.tsv, bom.xlsx, or
  bom.xls file alongside the Gerber files, the extension parses it and shows
  the rows in a sortable table below the board preview. CSV parsing is built
  in; Excel parsing uses a bundled copy of SheetJS that loads lazily on the
  first BOM encountered. Multi-sheet Excel workbooks get a sheet picker, with
  the sheet named "BOM" or "Bill of Materials" selected by default. Numeric
  and date cells are coerced to their display values so a date column reads as
  "2024-03-15" rather than as Excel's serial number 45366. A Copy as TSV button
  copies the current view to your clipboard in a spreadsheet-friendly format.
  
  ----------------------------------------
  Keyboard shortcuts
  ----------------------------------------
  
  Z fits the view, R rotates clockwise (Shift+R counter-clockwise), M toggles
  the measurement tool, U toggles between mm and mil, L / T / B switch to
  Layer / Top / Bottom views, O toggles the outline file, I inverts the theme,
  H hides the panel, and ? opens a help overlay listing every shortcut along
  with a note on how the measurement tool works.
  
  ----------------------------------------
  Gerber X2 and X3 attribute support
  ----------------------------------------
  
  When a Gerber file declares its role via %TF.FileFunction*%,
  %TF.GenerationSoftware*%, or related X2/X3 attributes, the preview header
  shows that information directly. So instead of guessing "is this top copper or
  bottom?" from a cryptic .gtl filename, you see "Top copper (L1) - KiCad 7.0.5"
  in the toolbar.
  
  ----------------------------------------
  Settings page
  ----------------------------------------
  
  Open via the Extensions menu (puzzle-piece icon) -> three-dot menu -> Options.
  Toggle the default measurement unit (mm or mil), default theme (light or
  dark), default outline mode, default panel collapsed state, and an optional
  cap on GitHub API calls per page. Settings persist across browser sessions.
  
  The Settings page also has a Copy Diagnostics button that writes a JSON blob
  to your clipboard with the extension version, your browser's user-agent, and
  the most recent 50 events (activations, file loads, errors). Useful for bug
  reports. The blob is purely local; nothing is sent anywhere.
  
  ----------------------------------------
  Privacy and security
  ----------------------------------------
  
  All parsing and rendering happens client-side, in your browser, on your
  machine. The extension does not send file contents to any server, ever. It
  does not collect telemetry. It does not run remote code. The only network
  requests it makes are to raw.githubusercontent.com and api.github.com (to
  fetch the files and folder listings you're viewing on GitHub), plus
  gist.githubusercontent.com when you're on a Gist page.
  
  The KiCanvas, SheetJS, tracespace, and fflate libraries are bundled inside
  the extension and loaded from the extension's own resources, not from any
  third-party CDN.
  
  Full privacy policy at the URL provided on the listing page.
  
  ----------------------------------------
  Built on tracespace, KiCanvas, fflate, and SheetJS
  ----------------------------------------
  
  The Gerber rendering pipeline is powered by the tracespace v4 toolkit
  (gerber-to-svg, pcb-stackup, whats-that-gerber) which is the same library set
  used by major online PCB review tools. ZIP support uses fflate. KiCad
  rendering uses KiCanvas. Excel BOM parsing uses SheetJS Community Edition. All
  five libraries are bundled directly into the extension; no remote code is
  fetched at runtime.
  
  ----------------------------------------
  Open source
  ----------------------------------------
  
  GPL-3.0 licensed. Source available at
  github.com/GreenShoeGarage/GitHub_GerberViewer_ChromeExtension. Bug reports
  and feature suggestions welcome.
  
  ----------------------------------------
  What's new in v0.9.3
  ----------------------------------------
  
  * Excel BOM support (.xlsx and .xls) via lazy-loaded SheetJS
  * Sheet picker for multi-sheet workbooks
  
  Recent versions (v0.9.x line):
  
  * v0.9.2: KiCad schematic (.kicad_sch) support, GitHub Gist support, keyboard
    shortcuts and help overlay, CSV BOM extraction, stackup layer visibility
    toggles
  * v0.9.1: Updated project URLs and homepage link
  * v0.9.0: Structured error handling with actionable suggestions, settings
    page, copy-diagnostics button

• May 19, 2026
  host_permissions

  https://raw.githubusercontent.com/*, https://api.github.com/*

  https://raw.githubusercontent.com/*, https://gist.githubusercontent.com/*, https://api.github.com/*

• May 13, 2026
  permissions

  (empty)

  storage

• May 13, 2026
  description

  Render Gerber and Excellon drill files inline on GitHub blob pages, with top/bottom multi-layer composite views.

  Preview PCB design files inline while browsing GitHub. No more downloading Gerber archives, unzipping them, and opening a separate tool just to see what a board looks like.
   
  Gerber Viewer for GitHub adds an interactive preview panel above the regular file view whenever you open a Gerber, Excellon drill, ZIP archive, or KiCad PCB file in a public or private repository. It works in three places:
   
  * On a single-file blob page (e.g. /blob/main/board.gtl), it renders the layer   immediately, then fetches sibling files in the same folder to build a realistic Top and Bottom composite view with copper, soldermask, silkscreen, and drill holes.
   
  * On a folder page (e.g. /tree/main/gerbers/), it detects layer-set folders automatically and shows the same composite view without needing to open an individual file first.
   
  * On a ZIP archive committed to a repo, it downloads and extracts the archive entirely in your browser, finds the Gerber files inside, and builds the same multi-layer preview.
   
  For KiCad .kicad_pcb files, the extension embeds the KiCanvas board viewer directly in the page, giving you full layer toggles, zoom, and pan over the native KiCad format.
   
  ----------------------------------------
  What's in the toolbar
  ----------------------------------------
   
  Layer / Top / In1 / In2 / ... / Bottom tabs to switch between views. Inner
  copper tabs appear automatically for multi-layer boards.
   
  Zoom controls with mouse-wheel zoom-to-cursor, step buttons, and Fit.
   
  Click-and-drag panning.
   
  Two rotation buttons for 90 degree steps.
   
  Chain measurement tool. Click two or more points to measure distances in mm
  or mil, with running totals shown in the status bar. Backspace undoes the
  last point, Escape exits.
   
  Outline toggle for boards whose .gko / Edge_Cuts file has disconnected
  segments, fab markings, or fiducials mixed into the boundary geometry. Flips
  between using the outline file and computing the boundary from the union of
  features.
   
  Invert (dark mode) for the rendered board.
   
  Download SVG of the current view at the current zoom.
   
  Hide / Show to collapse the panel without losing state.
   
  ----------------------------------------
  Gerber X2 and X3 attribute support
  ----------------------------------------
   
  When a Gerber file declares its role via %TF.FileFunction*%,
  %TF.GenerationSoftware*%, or related X2/X3 attributes, the preview header
  shows that information directly. So instead of guessing "is this top copper or
  bottom?" from a cryptic .gtl filename, you see "Top copper (L1) • KiCad 7.0.5"
  in the toolbar.
   
  ----------------------------------------
  Privacy and security
  ----------------------------------------
   
  All parsing and rendering happens client-side, in your browser, on your
  machine. The extension does not send file contents to any server, ever. It
  does not collect telemetry. It does not run remote code. The only network
  requests it makes are to raw.githubusercontent.com (to fetch the Gerber and
  drill files you're viewing) and api.github.com (to list the contents of the
  folder you're in).
   
  For .kicad_pcb files, the KiCanvas library is bundled inside the extension
  and loaded from the extension's own resources, not from any third-party CDN.
   
  ----------------------------------------
  Built on tracespace and KiCanvas
  ----------------------------------------
   
  The Gerber rendering pipeline is powered by the tracespace v4 toolkit
  (gerber-to-svg, pcb-stackup, whats-that-gerber) which is the same library set
  used by major online PCB review tools. ZIP support uses fflate. KiCad
  rendering uses KiCanvas. All five libraries are bundled directly into the
  extension; no remote code is fetched at runtime.
   
  ----------------------------------------
  Open source
  ----------------------------------------
   
  GPL-3.0 licensed. Source available at the project repository (see Website
  link below). Bug reports and feature suggestions welcome.
   
  ----------------------------------------
  What's new in v0.8.1
  ----------------------------------------
   
  * KiCad .kicad_pcb file support via the bundled KiCanvas library
  * Graceful fallback for systems where WebGL2 is unavailable, with file
    metadata and a raw-file download link
  * Inner copper layer browsing for 4+ layer boards (In1, In2, ... tabs)
  * Chain measurement mode with running totals and undo
  * Gerber X2 / X3 attribute parsing in the panel header
   
  Made by Green Shoe Garage.

• May 13, 2026
  short_description

  Render Gerber and Excellon drill files inline on GitHub blob pages, with top/bottom multi-layer composite views.

  Render Gerber, Excellon drill, ZIP archives, and KiCad PCB files inline on GitHub.

• May 13, 2026
  host_permissions

  https://github.com/*, https://raw.githubusercontent.com/*, https://api.github.com/*

  https://raw.githubusercontent.com/*, https://api.github.com/*

Permissions & access

Permissions

storage

Host access

https://raw.githubusercontent.com/*, https://gist.githubusercontent.com/*, https://api.github.com/*

Screenshots