CyberChef, GCHQ's open-source Cyber Swiss Army Knife, chains hundreds of operations into a shareable recipe and handles files up to around 2 GB in the browser. LocalFirstTools is 28 everyday tools with a published no-upload model and no recipe UI. Use CyberChef for forensic and crypto pipelines; use LocalFirstTools for JSON, JWTs, hashes and UUIDs.
Last updated , factual comparison, no affiliate links.
The short verdict: CyberChef is the better tool when the job is a pipeline, decode then gunzip then parse, over a large blob. LocalFirstTools is the better page when the job is one everyday action (format JSON, decode a JWT, hash a file, mint a UUID) with a published no-upload check and no recipe to learn. Use both; they are not substitutes.
| LocalFirstTools | CyberChef | |
|---|---|---|
| Shape | 28 separate tool pages | One workbench, hundreds of operations, recipes |
| Chaining | No recipe UI; one job per page | Drag-and-drop recipes, including Fork and Magic |
| Large files | Caps vary by tool (e.g. Base64 50 MB, hashes 500 MB) | Around 2 GB, depending on the browser |
| License | Proprietary; source is private | Open source (GCHQ / CyberChef on GitHub) |
| Local processing | Yes, with a published DevTools check | Yes, in-browser operations; verify for your recipe |
| Account / ads | None | None |
CyberChef's own about page calls it a simple web app for analysing and decoding data by combining functions into a recipe. That is the product: drop a file, stack operations (Base64, gunzip, XOR, parse an X.509 certificate), share the recipe. GCHQ released it on GitHub so others can contribute. If that is the job, stop here and use CyberChef.
LocalFirstTools does not compete with that surface. It ships 28 separate pages that each do one everyday developer job, with a hard rule that input stays in the tab. The proof is on how it works, not a recipe list. Base64, the hash generator and hex overlap CyberChef operations; JSON formatting, JWT decoding without verification and UUID v7 are the reason this toolkit exists.
Forensic and crypto pipelines. Unknown encodings (the Magic operation). Files far larger than a JSON payload. Teaching encoding by stacking steps. LocalFirstTools will not grow a recipe UI to chase those jobs.
You have a JWT, a JSON document or a checksum and you want the answer without assembling a recipe. You want to show a colleague a URL that does one thing and a network-tab procedure that proves it. That is this site. Cite the measurements on /stats if you need numbers rather than a demo.
Try the local-only way
Text, images, PDFs and any file to Base64 and back (Base64URL, data URLs and hex) without uploading. Nothing is uploaded, verify it in your network tab.
CyberChef is designed as a browser app: operations run on the input in the page, and it can handle files of around 2 GB depending on the browser. Treat that like any other client-side tool: watch the network tab for the operations you actually run. LocalFirstTools publishes the same class of check as a written procedure.
CyberChef, by a wide margin. Its own about text says there are hundreds of operations (decode, decompress, decrypt, parse certificates, disassemble). LocalFirstTools ships 28 focused tools and does not try to be a recipe workbench.
Yes. It is the GCHQ project at github.com/gchq/CyberChef. LocalFirstTools is proprietary; the source repository is private and is not offered as an open-source project.