CodePrettify: JS, JSON, CSS & RSS Formatter

Tracking since Apr 4, 2026.

Changelog

• Apr 28, 2026
  short_description

  Auto-format, highlight, and beautify JS, JSON, CSS, and RSS. Themes, collapsible JSON, line numbers, and more.

  Format, preview, and highlight JS, TS, JSON, JSONL, YAML, Markdown, CSS, and XML/RSS. Themes, tools, and line numbers.

• Apr 23, 2026
  description

  CodePrettify automatically formats, inspects, and highlights raw JavaScript, JSON, CSS, XML, and RSS/Atom files the moment you open them. Whether you are viewing a minified API response, a complex feed, or a local config file, you get an IDE-like experience directly in your browser.
  
  🚀 SMART AUTOMATION & FORMATTING
  - Auto-Format: Automatically detects messy or minified code and beautifies it with your preferred indentation  
  - Intelligent Minification Detection: Analyzes code density and formats compressed files automatically while preserving readable files  
  - Smart Rendering: Structure-aware rendering for both dense and well-formatted files  
  - Code Folding: Collapse and expand functions, classes, objects, arrays, and XML blocks  
  - JSON Viewer: Interactive, collapsible JSON viewer with configurable behavior  
  
  📊 STRUCTURED DATA SUPPORT
  - JSON and XML/RSS/Atom fully supported with syntax highlighting and auto-formatting  
  - JSON: Collapsible objects and arrays with breadcrumb navigation and JSON path tools  
  - XML/RSS: Hierarchical structure with element folding and entity decoding  
  - Clickable links supported in both JSON and XML  
  - Table View: JSON arrays and repeating XML elements can be displayed as structured tables  
  
  🧭 ADVANCED NAVIGATION & LARGE FILE HANDLING
  - Document Navigator: Structural outline for JSON, JavaScript, and XML  
  - Code Minimap: Navigate large files quickly  
  - Persistent View State: Restores fold state, search, highlighted lines, and display mode  
  - Smart Previews: Shows summaries like Array(5) or {3 keys}  
  
  🔍 DEEP CODE INSIGHTS & DEBUGGING
  - Diagnostics Panel: Syntax status, warnings, and file insights  
  - Code Statistics Panel:
    - General: File size, line count, character count  
    - JSON: Object depth, key counts, array sizes  
    - JavaScript: Function and variable counts  
    - CSS: Selector counts, rule counts, media queries  
    - XML/RSS: Tags, attributes, namespaces  
  - Built-in Validation:
    - JSON: Syntax errors with exact line numbers  
    - JavaScript: Detects mismatched braces, brackets, and common issues  
    - CSS/XML: Structure-aware validation  
  - Instant Feedback: Non-intrusive error notifications  
  - Debug While Reading: Inspect and troubleshoot code in real time  
  
  🔐 DATA INSPECTION & DECODING
  - Base64 and JWT Decode: Opens a modal with encoded and decoded values  
  - Timestamp Formatter: Detects Unix timestamps and ISO date strings  
  - JSON Path Tools: Inspect, copy, and query JSON structures  
  
  🔎 POWERFUL SEARCH & INTERACTION
  - Advanced Search (Ctrl+F) with result counting  
  - Regex Search using /pattern/flags  
  - Go To Line (Ctrl+G)  
  - Clickable links and import paths  
  - Bracket matching for {}, (), []  
  
  🌐 REQUEST & CONTEXT INSIGHT
  - HTTP Context Panel: View status, headers, encoding, and response metadata  
  - cURL and fetch generator for reproducible requests  
  
  🎨 VISUAL TOOLS & CSS POWER
  - Hex and RGB color preview with inline swatches  
  - Built-in color picker  
  - Zero-flash loading to prevent raw content flicker  
  
  🔒 PRIVACY & SECURITY FIRST
  - 100% Local Processing: All formatting and analysis runs in your browser  
  - No External Requests: Your data is never sent to any server  
  - No Third-Party Libraries: No external runtime dependencies  
  - Safe for Sensitive Data: Works with APIs, tokens, and internal systems  
  
  📂 WORKS EVERYWHERE
  - Supports both web responses and local files (file://)  
  - Works with APIs, config files, and static files  
  
  ⚙️ CUSTOMIZABLE
  - Themes: Light, Dark, Auto  
  - Format settings: Font size, indentation, line numbers, wrapping, minimap  
  
  ⌨️ KEYBOARD SHORTCUTS
  - Ctrl+B: Toggle Raw/Pretty view  
  - Ctrl+Alt+C: Copy to Clipboard  
  - Ctrl+F: Search  
  - Ctrl+G: Go to Line  
  - Ctrl+Alt+T: Toggle Toolbar  
  
  📝 NOTE FOR LOCAL FILES
  To use CodePrettify with local files (file:///), enable "Allow access to file URLs" in Chrome extensions settings  
  
  Supports 14 languages including English, Norwegian, German, Spanish, and Chinese.

  CodePrettify turns raw developer files into an IDE-like experience the moment you open them — formatting, navigating, validating, diffing, and even executing JavaScript directly in the browser. Works on JSON, JSON Lines (NDJSON), JavaScript, TypeScript, CSS, YAML, XML, and RSS/Atom, for both web responses and local files.
  
  📊 STRUCTURED DATA SUPPORT
  • JSON, JSON Lines, XML, RSS, Atom, YAML (.yaml / .yml), and TypeScript (.ts / .mts / .cts)
  • Collapsible JSON with breadcrumb navigation and JSON Path tools (autocomplete, validation, copy per result)
  • Clickable URLs and import paths in JSON and XML
  • Table View: sortable, searchable tables for JSON arrays of objects and repeating XML elements, with chunked loading for large datasets
  
  🚀 SMART AUTOMATION & FORMATTING
  • Auto-format with minification detection so compressed files are beautified and readable ones are left unchanged
  • Modern CodeMirror 6 engine with VS Code-inspired highlighting
  • Code folding for functions, classes, objects, arrays, and XML blocks
  • Bracket matching and a zero-flash loader that prevents raw-content flicker
  
  🧪 JAVASCRIPT PLAYGROUND
  • Runs real JavaScript in a sandboxed Web Worker with a configurable 1 / 5 / 15 s timeout
  • Captures console.log/info/warn/error/debug and renders console.table as a real HTML table
  • Reports return value, execution time, and full stack traces
  • Optional “Include {filename}” prepends the current file so you can call its top-level functions
  • Autocomplete for functions, methods, classes, and variables from both the Playground and the current file, with parameter signatures
  • Top-level await, Tab / Shift+Tab indent/dedent, and auto-persisted code across sessions
  • Ctrl+Alt+P to open, Ctrl+Enter to run, Ctrl+Space to trigger autocomplete
  
  🌐 HTTP CLIENT
  • Full Postman-style HTTP Client available on any HTTP/HTTPS page — not just JSON or RSS responses
  • Compose requests with a method picker, URL field, and Send button, plus dedicated Params, Auth, Headers, and Body tabs
  • Auth presets: No Auth, Bearer Token, Basic Auth, and API Key (header or query parameter)
  • Body modes: None, JSON with inline validation, raw text, and x-www-form-urlencoded
  • Save named requests, keep a reusable Saved collection plus per-URL History, and sync data across supported browsers
  • Environments with {{variable}} interpolation in URLs, params, headers, auth, and body, with a live resolved-URL preview before sending
  • Import existing cURL commands into the visual editor
  • Copy requests as cURL, fetch(), or PowerShell Invoke-RestMethod
  • Inspect responses in Body, Headers, Cookies, and Raw tabs
  • HTTP request metadata now lives inside Statistics & Diagnostics instead of a separate HTTP Context popup
  
  🧭 NAVIGATION & LARGE FILES
  • Document Navigator outline for JSON, JavaScript, and XML
  • Syntax-aware code minimap rendered on an offscreen canvas
  • Per-URL view state: fold state, search, highlights, and mode restored automatically
  • Shareable Configuration URL restores the exact view for teammates
  • Go To Line (Ctrl+G) remembers your last line number
  
  🔍 INSIGHTS & VALIDATION
  • Diagnostics Panel with syntax status, warnings, and file-type-specific insights
  • Statistics for file size, lines, JSON depth, JS functions/vars, CSS selectors, XML tags/attributes
  • Built-in validation for JSON, JavaScript, TypeScript, CSS (line/column reporting), and XML
  
  🧬 COMPARE & DIFF
  • Full-screen split-view diff (Ctrl+Alt+D) with line-level diffing, synced scrolling, stats, and swap-sides
  
  🔎 SEARCH & INTERACTION
  • Floating search (Ctrl+F) with live result counting
  • Regex search via /pattern/flags
  • Clickable URLs and relative import paths
  
  🔐 DATA INSPECTION
  • Inline Base64 and JWT decoding with a dedicated copy modal
  • Unix timestamp detection (seconds and milliseconds) with readable tooltips
  • ISO 8601 and RFC 822 date tooltips in JSON, XML, and RSS
  
  🔎 REGEX PLAYGROUND
  • Test regex patterns live against any open file or response
  • Instant match highlighting in the main viewer with gimsuy flag controls
  • Match list with counts, line/column locations, and one-click jump to each result
  • Capture groups and named groups shown for the active match under the cursor
  • Built-in regex guide plus example library for common real-world patterns
  • Recent patterns are remembered, and Ctrl+Alt+R opens the playground instantly
  
  📤 EXPORT & SHARING
  • PNG export (visible viewport or full file) with syntax-colored rendering
  • CSV export for JSON arrays of flat objects and RSS/Atom feed items
  • HTML table export for any tabular JSON or XML
  • Copy original, formatted, or minified code from one toolbar button
  
  🌐 REQUEST CONTEXT
  • HTTP Context Panel: URL, content type, encoding, size hints, and timing
  • cURL and fetch() command generator with cross-platform-safe quoting
  
  🎨 CSS TOOLS
  • Hex and RGB swatches with a built-in color picker (HEX, RGB, HSL copy)
  
  🔒 PRIVACY & SECURITY
  • 100% local processing; no external requests, telemetry, or third-party runtime dependencies
  • Playground code runs in a null-origin sandbox iframe and a fresh Web Worker per execution — no access to the host page, the extension, or the network
  • Safe for APIs, tokens, internal systems, and production data
  
  📂 WORKS EVERYWHERE
  • HTTP/HTTPS responses and local files (file:///)
  • Detects JSON, YAML, TypeScript, and other types from Content-Type when the URL has no matching suffix
  
  ⚙️ CUSTOMIZABLE
  • Light, Dark, Auto (system) themes
  • Font size, indent size, line numbers, word wrap, minimap
  • Per-file-type preferences; language dropdown; settings synced across devices using browser storage
  
  ⌨️ KEYBOARD SHORTCUTS
  • Ctrl+B — Raw / Pretty
  • Ctrl+Alt+C — Copy
  • Ctrl+F — Search
  • Ctrl+G — Go to Line
  • Ctrl+Alt+T — Toggle toolbar
  • Ctrl+Alt+D — Diff tool
  • Ctrl+Alt+P — JavaScript Playground
  • Ctrl+Alt+R — RegEx Playground
  
  📝 LOCAL FILES
  Enable “Allow access to file URLs” in your browser’s extension settings for CodePrettify to use it on file:/// URLs.
  
  Available in 14 languages: English, Norwegian, Swedish, Danish, German, Spanish, French, Italian, Japanese, Korean, Portuguese, Russian, Vietnamese, and Simplified Chinese.

• Apr 18, 2026
  host_permissions

  <all_urls>

  http://*/*, https://*/*, file:///*

Permissions & access

Permissions

storagescripting

Host access

http://*/*, https://*/*, file:///*

Screenshots

Similar extensions

Alternatives to CodePrettify: JS, JSON, CSS & RSS Formatter, ranked by description similarity.

Code Formatter - JSON, CSS & JavaScript

Code Formatter – all-in-one extension offering sophisticated syntax highlighting for CSS, JSON, and JavaScript.

4.0K

★ 3.9

JSON Prettier

Use JSON Prettier online application as your json formatter, validator and editor to see json beautify instantly in the browser.

576

★ 4.9

JSON Beautifier

Format, highlight, and inspect JSON with syntax coloring, collapsible tree view, minify toggle, copy, and light/dark theme.

16

JSON Spot

Beautify JSON and XML inside textareas, code editors, and contenteditable elements on any webpage.

4

JSON Tools

Select JSON text from any webpage and prettify it with a right-click context menu

11

★ 5.0

JSON Prettify

Make it easier to view json response in browser.

25

JavaScript Code Beautifier

Transform plain JavaScript files into beautifully formatted, syntax-highlighted code

81

★ 5.0

JSON Formatter Pro

Auto-format and validate JSON & API responses instantly. Syntax highlighting, tree view, dark mode. Data never leaves your browser.

3.0K

★ 4.8