OmniJSON

Stream and browse 50MB+ JSON in a dedicated viewer—search while parsing, match navigation, JSONPath Lite, local-only.

OmniJSON is a local JSON workbench for Chrome. Open and explore JSON from anywhere—URLs, APIs, exports, or local files—in a **dedicated viewer** that streams bytes in the background (Offscreen + Worker + Rust/WASM). Browse, filter, and copy paths while data loads—**without replacing the JSON page in your tab**. ### Why OmniJSON - **Large JSON, responsive UI** — Progressive parsing and a virtualized tree; from ~50MB or ~500k nodes, a lighter browsing mode keeps scrolling smooth. - **Search while loading** — Keyword filter on keys and scalars during parse; full JSONPath after parsing for regular documents, and JSONPath Lite structural paths for large documents; **Prev/Next** match navigation with live match count after filtering. - **Copy paths that match your stack** — JSONPath, JavaScript path, jq path, key path, values, and subtree JSON. - **Trust by design** — All processing happens locally in your browser. No uploads, no analytics, and no data ever leaves your device. MIT open source. ### Key features - Dedicated extension viewer for raw JSON from URLs, APIs, exports, or local files (original tab unchanged) - Stream and progressively parse large documents - Virtualized tree—expand/collapse without rendering the whole document - Keyword search on keys and scalar values while parsing - Match count and **Prev/Next** navigation after filtering (Worker/WASM lookup; no full match arrays in large-document mode) - JSONPath queries after parsing completes; large documents support JSONPath Lite structural paths such as `$.items[*].id`, `$.items[0]`, and `$..id` - Scalar previews: long strings, URLs, timestamps, escaped JSON, large integers; large documents load a Value Inspector on demand when a scalar is selected - Parse progress and phase timing (network, chunks, parse, finalize) ### Works alongside other extensions Keep your favorite **in-tab JSON formatter** for small pages; open OmniJSON when you need a full-workbench view of large JSON from URLs, APIs, exports, local files, or configs. ### Large documents - Browse while parsing is still in progress (first tree rows before the full download completes). - From ~**50MB+** or **500,000+ nodes**, switches to **Row Window mode**—only visible rows reach the tree; the full dataset stays in Worker/WASM memory. - Large-document mode supports JSONPath Lite structural paths; predicates, slices, unions, functions, and comparisons remain regular-document full JSONPath features. - Status UI shows whether delay is network or parsing. ### Reference performance Desktop Chrome reference runs (paste URL → open viewer → read header **total time** and panel **Worker parse**): | Sample | Size | Total | Worker parse | |--------|------|-------|----------------| | GEM `submission.json` sample on Hugging Face | 4.9 MB | **1.64 s** | 108 ms | | `2023-04-12_oasst_alpaca_ready.trees.json` (HF fetch) | 86.7 MB | **10.1 s** | 3.06 s | | twitter-sentiment `test.json` sample on Hugging Face | 188.8 MB | **26.3 s** | 6.84 s | Large files are often **network-bound** (~28 MB/s Worker parse vs ~8 MB/s download on the 189 MB sample). Timings vary by hardware, browser version, cache, and network. Phase metrics in the viewer show whether delay is network or parse. ### Best for Developers, QA, data engineers, and SREs who regularly open JSON in the browser—from remote URLs and API responses to local exports, webhook payloads, and nested configs—especially at 50MB+ scale. ### Scope - Single raw JSON documents (object, array, API response, local file). - No in-tab auto-formatting; no jq query execution (jq-style **path copy** only). - Very large subtree copy is size-limited; oversized copy requests return an error instead of blocking the Worker. - Not a general text editor or arbitrary log search tool. ## Privacy summary (listing) OmniJSON processes JSON locally in your browser. It does not upload parsed JSON, page contents, cookies, credentials, copied values, or usage data to external servers. No usage analytics. No ads. No remote formatting.