Huge-size JSON Viewer GUI · formerly Huge JSON Viewer
Open and search very large JSON files (2–3 GB and up) on macOS and Windows in seconds — a free, open‑source alternative to Dadroit. When your text editor or browser crashes on a big JSON file, this opens it instantly.
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Most text editors and online JSON viewers crash or freeze when you open a large JSON file, because they parse the whole thing into memory — a 2–3 GB file balloons to 15–30 GB of RAM. BigJSON never does that. It memory‑maps the file, builds a compact index in one streaming pass, and renders only the rows on screen. So it opens multi‑gigabyte JSON in seconds and searches the whole file instantly, staying under ~1.5–2× the file size in RAM.
If you've searched for "how to open a large JSON file", "JSON file too big to open", or a free Dadroit alternative for Mac or Windows, this is built for exactly that.
- ⚡ Opens 2–3 GB JSON in ~3 seconds — memory‑mapped, streaming index, virtualized tree
- 🔍 Search keys and values — case‑sensitive or not, plain or regex, live match count, next/prev with jump‑to‑match that auto‑expands the path
- 📤 Convert JSON → CSV or XML — streaming export that works on multi‑GB files (a huge array of objects becomes a spreadsheet)
- 📋 Copy & extract — right‑click any node to copy its key, value, path (jq‑style, e.g.
.users[3].name), or copy / export a subtree as JSON - 🔗 Union multiple files — open several JSON files at once as one combined, searchable tree
- 🌳 Syntax‑highlighted collapsible tree with line numbers, indent guides, type colors and child counts (Dadroit / jsonviewer.app style)
- 📄 Opens
.json,.ndjson/.jsonl(auto‑detected),.geojson,.txt— or paste JSON straight from the clipboard - 🖱️ Drag‑and‑drop, ⌘O / Ctrl+O to open, ⌘V / Ctrl+V to paste, ⌘F / Ctrl+F to search, full keyboard navigation
- 🔔 Update notice — a subtle status‑bar link when a new version ships (checked at most once a day; fully offline‑safe)
- 🌍 20‑language UI, right‑to‑left aware (Arabic, Urdu, Punjabi)
- 🖥️ macOS & Windows — universal Mac (Apple Silicon M1–M4 + Intel) and Windows 10/11 (x64)
- 🔒 Your files never leave your device — no file upload, no server, ever · only anonymous, opt‑out usage stats · tiny app
- 🆓 Free and open source (MIT)
- Download the latest
.dmgand open it. - Drag BigJSON into Applications.
- First launch: the app is unsigned, so right‑click the app → Open, then confirm (only needed once).
Requirements: macOS 11 (Big Sur) or newer, Apple Silicon or Intel.
- Download the latest
.exe(theBigJSON_x.y.z_x64-setup.exeNSIS installer) and run it — it installs per‑user, no admin needed. - The build is unsigned, so if SmartScreen appears, click More info → Run anyway (only needed once).
Requirements: Windows 10 or 11 (64‑bit). WebView2 is preinstalled on Windows 11 and current Windows 10; the installer fetches it automatically if missing.
Both builds handle JSON files up to 4 GB.
A 2–3 GB JSON file cannot be parsed into in‑memory objects. The Rust core instead:
- Memory‑maps the file (
memmap2) — paged in on demand by the OS, not held on the heap. - Streams a single tokenizer pass to build a compact flat index (~23 bytes per JSON node) of byte offsets and structure — never parsed objects.
- Renders only visible rows. The tree is fully virtualized; expand/collapse mutate a visible‑row list instead of materializing the whole document. A scaled scrollbar keeps millions of rows scrollable past the browser's element‑height limit.
- Searches raw bytes with SIMD substring / regex over the mmap and maps every hit back to its node.
Built with Tauri v2 (Rust backend + web frontend), packaged as a ~2 MB .dmg (macOS) or NSIS .exe installer (Windows).
A factual, feature‑by‑feature comparison. BigJSON is the free, open‑source Dadroit alternative: everything below — large files, search, CSV/XML export, multi‑file union, commercial use — is included at no cost, where Dadroit gates it behind $98–$198/yr paid tiers.
| BigJSON | Dadroit | Text editors (VS Code, etc.) | |
|---|---|---|---|
| Price | Free & open source (MIT) | Free non‑commercial, ≤ 50 MB · $98/yr (≤ 2 GB) · $198/yr (≤ 1 TB) | free / paid |
| Commercial use | ✅ free | 💲 paid ($98/yr+) — free tier is non‑commercial | ✅ |
| Open source | ✅ MIT, auditable | ❌ closed source | mixed |
| Free up to | 4 GB | 50 MB, then paid | — |
| Max file size | 4 GB / file | 1 TB (paid tier) | ~a few hundred MB before it chokes |
| Opens 2–3 GB JSON | ✅ ~3 s | ✅ (paid tier) | ❌ crashes / freezes |
| Raw open throughput | fast (~1 GB/s, CPU‑bound) | very fast (vendor claim ~2 GB/s) | slow |
| RAM for a 3 GB file | ~1.5–2× (index; the mapped file stays reclaimable page cache) | ~1× (vendor claim) | often out‑of‑memory |
| Collapsible tree viewer | ✅ | ✅ | ❌ (raw text) |
| Search keys & values | ✅ | ✅ | limited |
| RegEx search | ✅ | ✅ | ✅ |
| Convert → CSV / XML | ✅ free | ✅ | ❌ |
| Export / copy subtree as JSON | ✅ | node‑level export | manual |
| Copy key / value / path (jq‑style) | ✅ | value + export | manual copy‑paste |
| Union multiple files | ✅ free | 💲 paid tier | ❌ |
| NDJSON / JSON Lines | ✅ auto‑detected | ✅ | ❌ |
| Auto‑refresh on file change | ❌ | ✅ | some |
| Edit JSON | ❌ view‑only | ❌ view‑only | ✅ |
| Platforms | macOS (universal) · Windows | Windows · macOS · Linux | all |
| UI languages | 20 (RTL‑aware) | few | many |
| Your files never leave your device | ✅ | ✅ | ✅ |
| Install size | ~2–5 MB | tens of MB | — |
The short version: for JSON up to a few GB, BigJSON does everything Dadroit's paid tiers do — open, regex‑search, convert to CSV/XML, union multiple files, extract subtrees — for free, open source, with no commercial‑use or feature paywall. Dadroit's free tier stops at 50 MB and forbids commercial use; unlocking 2 GB / commercial costs $98/yr, and 1 TB + the full feature set costs $198/yr.
Where Dadroit still leads (honestly): files beyond 4 GB (up to 1 TB), native Linux builds, auto‑refresh when a file changes on disk, and higher raw throughput on its own benchmarks. If you routinely open 100 GB–1 TB files or need Linux, Dadroit earns its license. For everything up to a few gigabytes, BigJSON is the free, unlimited choice.
Dadroit tiers and pricing per dadroit.com (subject to change). Speed/RAM figures are each project's own claims — benchmark your own files to compare.
The UI ships in 20 locales, switchable from the 🌐 button (persisted, auto‑detected on first launch). Right‑to‑left locales mirror the interface while keeping the JSON tree left‑to‑right; numbers format per locale.
en-US · zh-CN · hi-IN · es-ES · fr-FR · ar-EG · bn-BD · ru-RU · pt-BR · id-ID · ur-PK · de-DE · ja-JP · sw-TZ · mr-IN · te-IN · pa-PK · zh-WUU · ta-IN · tr-TR
Prerequisites: Node.js 20+, the Rust toolchain, and the Tauri v2 system prerequisites for your OS (Xcode Command Line Tools on macOS; Microsoft C++ Build Tools + WebView2 on Windows).
npm install
npm run tauri dev # hot-reloading dev app
npm run tauri build -- --target universal-apple-darwin --bundles dmg # macOS universal DMG
npm run tauri build -- --bundles nsis # Windows installer (run on Windows)
cd src-tauri && cargo test # engine tests (serde_json oracle, escapes, NDJSON, search)- File size: up to 4 GB (compact
u32offsets). Larger files are rejected with a clear message. - RAM: the index is ~23 bytes/node, so a 2–3 GB file needs roughly 1.5–2× the file size in RAM (the memory‑mapped file itself is evictable OS page cache). A 16 GB machine handles 2–3 GB files comfortably.
- Search matches raw file bytes (an escaped character matches in its escaped form); case‑insensitive matching is ASCII‑only.
MIT © bandusix
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