Mermaid Previewer (Fork)

Preview and export mermaid.

As of June 2026, Mermaid Previewer (Fork) has 24 users in the Developer Tools category.

Usersno change0%
24
24
Ratingno change0%
— reviews
Reviewsno change0%
Version
1.6.0
Manifest V3
90-day change · In the last 90 days this extension 1 version update.

History

6 snapshots

Tracking since Apr 28, 2026.

24.81913.2Apr 28, 2026Jun 11, 2026
View as table
DateUsersRatingReviewsVersion
Apr 28, 20261.5.2
May 5, 20261.5.2
May 22, 20261.6.0
May 29, 2026141.6.0
Jun 5, 2026191.6.0
Jun 11, 2026201.6.0
Now241.6.0

Permissions & access

Permissions
storagedownloadsactiveTabscripting
Host access
https://*/*, file:///

Screenshots

Mermaid Previewer (Fork) screenshot 1

About

Fork of https://github.com/zephyraft/mermaid-previewer to include support for Firefox, add dark mode, and support Bitbucket Pull Request Descriptions.

This fork adds support for Firefox, auto detected dark mode, Bitbucket Pull Request rendering (description + diff views), and configurable diff selectors.

Test the extension here: https://bitbucket.org/marcozaccari2/markdown-diagrams-browser-extension/src/master/doc/examples/mermaid.md

Fork Changes:

- Firefox Support: Mermaid runs in the page's MAIN world to avoid Firefox CSP restrictions. A bridge script handles cross-world communication via postMessage.
- Dark Mode: Automatically detects prefers-color-scheme: dark and uses mermaid's dark theme.
- Bitbucket PR Description Rendering: Renders mermaid in PR description code blocks.
- Diff View Rendering: Extracts mermaid from fenced code blocks in git diff views and renders diagrams inline. Works with both unified and side-by-side diffs.
- Configurable Diff Selectors: Diff rendering is configurable in the extension settings page with match patterns, diff wrapper selectors, code line selectors, and fence markers. Default config targets Bitbucket pull request diffs.
- Download JPG: Adds a download JPG button in addition to the Download SVG button.
- Fullscreen view: Adds a fullscreen button to see diagrams in fullscreen.

A Chrome/Firefox extension for previewing and exporting mermaid images in web pages, fully rendering mermaid locally without involving remote API calls.

On websites that meet the preset rules, you can preview or export by setting the code block language in markdown to mermaid:

At the same time, it also provides the function of custom rule configuration. This is a fork of https://www.github.com/zephyraft/mermaid-previewer. Thank you to @zephyraft!

Preset Rules:

Exclude URLs:
- https://chromewebstore.google.com/*

Matching Selectors:
- div.codehilite > pre under *://bitbucket.org/* (Support Bitbucket preview and export)
- #pull-request-description-panel [data-ds--code--code-block] > code under *://bitbucket.org/* (Support Bitbucket PR description mermaid rendering)
- body > pre under file:///*.mmd and file:///*.mermaid (Support preview and export of .mmd and .mermaid files)

Download Selectors:
- div.mermaid-view div.mermaid under https://viewscreen.githubusercontent.com/markdown/mermaid* (Support GitHub export)
- div#app under https://gitlab.com/-/sandbox/mermaid (Support Gitlab export)

Diff Selectors:
- .bitkit-diff-wrapper-diff with .code-diff under *://bitbucket.org/*/pull-requests/* (Renders mermaid diagrams found in Bitbucket PR diff views)

Technical

Version
1.6.0
Manifest
V3
Size
1.9MiB
Min Chrome
88
Languages
1
Featured
No

Metadata

ID
haamgcnhjkmednjhdclkfonbmflcikel
Developer ID
ud3b84190dc05f37eb733966ec316310f
Developer Email
[email protected]
Created
Apr 27, 2026
Last Updated (Store)
Apr 30, 2026
Last Scraped
Jun 11, 2026
Website
Support URL

Data sourced from the Chrome Web Store · last verified Jun 11, 2026.