Fast, native desktop JSON viewer for large files. Open 100MB, 500MB, even multi-GB JSON files instantly. Built with Tauri, Rust (simd-json), and React. A free, open-source alternative to Dadroit for inspecting big JSON, log dumps, API exports, and analytics datasets that crash VS Code, Sublime Text, and other text editors.
Keywords: huge JSON viewer · large JSON file viewer · JSON viewer 100MB · big JSON file editor · fast JSON parser desktop app · Dadroit alternative · macOS JSON viewer · Windows JSON viewer · Linux JSON viewer · open large JSON file · JSONPath search GUI · JSON tree viewer.
Latest release: github.com/hi-malay/bigJson/releases/latest
- macOS (Intel + Apple Silicon, universal): bigJson_0.1.0_universal.dmg
- Windows (x64): bigJson_0.1.0_x64-setup.exe
- Linux AppImage (x64): bigJson_0.1.0_amd64.AppImage
- Linux .deb (Debian/Ubuntu): bigJson_0.1.0_amd64.deb
All builds are unsigned. First-launch workarounds:
- macOS: right-click → Open, or run
xattr -cr /Applications/bigJson.app - Windows: SmartScreen blocks it → click "More info" → "Run anyway"
- Linux AppImage:
chmod +x bigJson_*.AppImage && ./bigJson_*.AppImage
VS Code and other text editors treat JSON as editable text UTF-16 string in RAM, tokenizer, syntax highlighter, undo buffer, plugins. That's why they freeze on 100MB+ files. Online JSON viewers can't handle anything past ~10MB and you'd never paste private data there anyway. bigJson is a read-only viewer that parses the file natively in Rust, builds a flat index of every node, and renders only the rows visible on screen. RAM usage stays close to the file size instead of 3-10×.
- Open huge JSON files instantly 100MB in under a second, no UI freeze.
- Virtualized tree millions of nodes scroll smoothly because only ~50 visible rows render at a time.
- Lazy expansion children load on demand, even arrays with hundreds of thousands of entries.
- Text search across keys and values (case-insensitive).
- JSONPath search
$.users[*].email,$.orders[?(@.total > 1000)], etc. - Copy node value (pretty-printed subtree) or copy JSONPath for any node.
- Drag-and-drop files onto the window, or use the ⌘O shortcut.
- Native macOS, Windows, and Linux builds. No browser required.
- Open source under MIT. Built with Tauri 2, Rust, and React.
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| Empty state drag-drop or ⌘O to open | Text search across keys + values |
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| Lazy virtualized tree | JSONPath mode |
npm install
npm run tauri dev # dev, ~1 min first compile
npm run tauri build # release .app / .dmgnode scripts/gen-fixtures.mjs # tiny / small / medium JSON in fixtures/React + Vite + Tailwind 4 ←→ Tauri commands ←→ Rust (simd-json + flat index)
src/ is the frontend. src-tauri/src/ is the Rust core (parser.rs, index.rs, search.rs, commands.rs). The Index is a flat Vec<Node> plus a child_ids arena node-id lookups are O(1), no per-node heap allocations beyond the previews.
Files larger than RAM, raw text view, diff editor, code-signing/notarization. v2.
How big a JSON file can bigJson open? On a machine with 16GB of RAM it comfortably opens JSON files up to ~3GB. v2 will add memory-mapped streaming for files larger than RAM.
Is bigJson free? Yes MIT licensed, no telemetry, no ads, no sign-in.
Does bigJson work offline? Yes. It's a native desktop app no network calls, no cloud parsing, no data leaves your machine.
Does bigJson edit JSON or just view it? View only. The goal is fast inspection of large files; an edit mode would require an undo stack and other machinery that defeats the speed advantage.
Is bigJson a Dadroit alternative? That's the inspiration. bigJson is open-source and free. Dadroit is closed-source with a free tier.
Why does macOS / Windows warn on first launch? The release binaries are unsigned (no Apple Developer Program / Authenticode signing fees yet). See the Download section for one-line workarounds per OS.
json json-viewer large-json huge-json json-parser tauri rust react desktop-app macos windows linux simd-json jsonpath developer-tools dadroit-alternative data-inspection log-viewer