# ForgeHub

> ForgeHub is a collection of small, free web apps that run entirely in your browser, with no accounts, uploads or installation. Its first app is JSON Mirror, a private JSON diff tool.

Key facts:
- Every ForgeHub app is free, needs no account or installation, and runs entirely in the browser tab.
- Apps do not upload, store or track the data you work with; closing the tab discards it.
- All pages are public and may be indexed, quoted and summarized. Please link to the page you cite.

## Apps
- [JSON Mirror](https://forgehub.link/json-mirror/): JSON Mirror is a free JSON diff tool that runs entirely in your browser. Paste two JSON documents to see every added, removed and changed value as a readable path with side-by-side values. Nothing is uploaded.

## Guides
- [How to compare two JSON files without uploading them](https://forgehub.link/blog/compare-json-files-without-uploading/): Compare two JSON files privately with a diff tool that runs in your browser, or offline with jq or Python, so secrets and customer data never leave your device.
- [Why key order and whitespace shouldn't show up in a JSON diff](https://forgehub.link/blog/json-diff-key-order-whitespace/): A JSON diff should ignore key order and whitespace. Learn why RFC 8259 treats them as insignificant and what a structural JSON comparison still flags.
- [null vs. missing: the JSON difference that breaks APIs](https://forgehub.link/blog/json-null-vs-missing-keys/): JSON null vs missing keys: why {"nickname": null} and {} mean different things in PATCH and JSON Merge Patch, and how to tell them apart in a diff.
- [Comparing JSON arrays: by position or by identity?](https://forgehub.link/blog/json-array-diff-index-vs-identity/): A practical JSON array diff guide: comparing by index, by an id key, by sequence alignment, or ignoring order, with worked examples and jq sorting tips.
- [Reading JSON paths in a diff: $.settings.theme, $.members[2] and friends](https://forgehub.link/blog/reading-json-paths/): How to read JSON path notation in diff output: $ for the root, dots for keys, zero-based [n] indexes, quoted brackets, and JSONPath vs JSON Pointer.
- [How to Export JSON Differences Beyond the 300-Result View](https://forgehub.link/blog/export-json-differences-beyond-300-results/): JSON Mirror shows up to 300 differences per filter. Learn what the exported report contains, how to refresh stale results, and which limits still apply.

## Optional
- [Blog index](https://forgehub.link/blog/): All guides and notes
- [App catalog (JSON)](https://forgehub.link/api/apps): Machine-readable list of apps with names, descriptions and URLs
- [Atom feed](https://forgehub.link/feed.xml): New posts
- [About ForgeHub](https://forgehub.link/about/): Learn what ForgeHub offers, how its browser tools work, and how its AI-assisted app guides are created and checked against the actual implementation.
- [Privacy policy](https://forgehub.link/privacy/): How ForgeHub handles your data: apps run in your browser, nothing you enter is uploaded, and there are no accounts, analytics, advertising or tracking cookies.
- [Terms of use](https://forgehub.link/terms/): The terms for using ForgeHub's free browser tools and articles: acceptable use, your responsibility for your data, content reuse, and the no-warranty basis.
- [Full text](https://forgehub.link/llms-full.txt): Every app description and guide in one Markdown file