Markdown viewer & structured-data toolkit

View Markdown with Mermaid, diff JSON & XML — right in your browser.

A fast, privacy-first toolkit: open .md files with diagrams, math & footnotes, plus diff, format, validate & explore JSON, XML, YAML & CSV. Everything runs locally — nothing is uploaded.

Open Markdown Viewer Browse all tools ↓
100% client-side · no account · works offline

Eight tools, one engine

every operation, every format

Why it’s different

Private

Provably private

Runs entirely in your browser. Nothing is uploaded unless you share it — and a share is encrypted before it leaves.

Unified

One engine, every format

Diff, format, validate, and explore share the same core across each supported format.

Fast

Keyboard-first

Run any tool with ⌘↵. No mouse round-trips, no layout shift.

Free

Free, no login

No accounts, no paywalls, no ads. The core tools stay free forever.

Markdown viewer, editor & structured-data toolkit — all in your browser

Bracepad is a free, privacy-first collection of eight web tools. Start with the Markdown Viewer: open local .md files fully rendered with Mermaid diagrams, KaTeX math, footnotes, GFM tables, task lists, in-document search, clickable outline, and export to PDF, HTML or Word. Drop a folder of Markdown and images, and relative image links resolve locally so docs render exactly as they would on GitHub.

The same suite also covers structured data for developers: a diff checker (text, JSON, XML) with word-level highlighting, a beautifier / formatter and minifier for JSON, XML, YAML and CSV, a syntax validator with line-column diagnostics, and a tree explorer with JSONPath queries and copyable node paths. Completing the set are a Workspace for nested pages and notes (backlinks, tables, Mermaid, math, lossless markdown import/export) and an infinite Canvas whiteboard (freehand, hand-drawn shapes, real editor inside text boxes and tables).

Every tool runs entirely in your browser: nothing you paste, open, or draw is uploaded, logged, saved to a share link, or indexed. That makes Bracepad safe for configs, API responses, internal docs, and payloads that contain secrets. All eight tools share one engine and one design system, with a keyboard-first workflow (⌘↵ to run, ⌘K to jump between tools), dark and light themes, no layout shift, and offline support once loaded. It is free, needs no account, and stays free forever for the core tools.

Is any of my data sent to a server?

Not unless you ask for it. Every operation — rendering Markdown, comparing JSON, drawing on the canvas, importing files — is 100% client-side JavaScript, and with no account nothing you write leaves the browser tab. The two things that do send anything are both deliberate acts: a share link, and turning on sync for a signed-in account. Both are end-to-end encrypted — the server stores ciphertext it cannot read.

Which Markdown features does the viewer support?

CommonMark plus GFM (tables, strikethrough, task lists, autolinks), footnotes, heading anchors with a clickable outline, Mermaid code fences (flowchart, sequence, class, state, ER, gantt, pie, mindmap, timeline, quadrant, sankey, etc.), $…$/$$…$$ KaTeX math, fenced code with syntax highlighting, reading modes, in-document search, recent files, local-relative image resolution via folder access, and export to PDF, standalone HTML, or Word (.docx).

Which structured-data formats are supported?

JSON, XML, YAML, and CSV across the beautify, minify, validate, and tree tools. The diff checker compares plain text, JSON, and XML with structure-aware normalization so a re-ordered object compares cleanly.