Yes. MIT licensed, open source, no telemetry, no ads, no sign-in.

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.

Why does macOS or Windows warn on first launch?

The release binaries are unsigned. macOS: right-click → Open, or run xattr -cr /Applications/bigJson.app. Windows: SmartScreen → More info → Run anyway.

bigJson huge JSON file viewer

Q: How big a JSON file can bigJson open?

On a machine with 16GB RAM it opens JSON files up to ~3GB comfortably. v2 will add memory-mapped streaming for files larger than RAM.

Q: Does bigJson work offline?

Yes — it is a native desktop app. No network calls, no cloud parsing, no data leaves your machine.

Q: Is bigJson a Dadroit alternative?

That is the inspiration. bigJson is open source and free. Dadroit is closed source with a free tier.

macOS · Windows · Linux · Free · Open Source · MIT

Fast, native desktop viewer for large JSON files. Open 100MB, 500MB, even multi-gigabyte JSON instantly. Built with Tauri, Rust (simd-json), and React. The open-source alternative to Dadroit for inspecting huge JSON dumps, API exports, analytics datasets, and log files that crash VS Code, Sublime Text, and other text editors.

Download latest View on GitHub macOS .dmg Windows .exe Linux AppImage

bigJson screenshot desktop viewer for huge JSON files with virtualized tree and JSONPath search

Why bigJson

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 into them 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×.

Features

Open huge JSON files

100MB in under a second; multi-GB on a 16GB machine.

Virtualized tree

Millions of nodes scroll smoothly. Only visible rows render.

Lazy expansion

Children load on demand, even for huge arrays.

JSONPath search

$.users[*].email, $.orders[?(@.total > 1000)], etc.

Text search

Case-insensitive substring across all keys and values.

Copy node or JSONPath

Pretty-printed subtree, or the exact path to clipboard.

Cross-platform

Native builds for macOS (universal), Windows, Linux.

Offline + private

No network calls. Nothing leaves your machine.

Install

macOS: download the .dmg, drag bigJson to Applications. On first launch right-click → Open, or run xattr -cr /Applications/bigJson.app.
Windows: run the .exe installer. SmartScreen will warn click "More info" → "Run anyway".
Linux: chmod +x bigJson_*.AppImage && ./bigJson_*.AppImage, or install the .deb.

FAQ

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.

Is bigJson a Dadroit alternative?

That's the inspiration. bigJson is open-source and free. Dadroit is closed-source with a free tier.