JWT Generator — Token Builder
Generate JWT tokens with custom claims, expiry, and algorithm selection for testing and prototyping.
How it works
- 1Configure your options above
- 2Click "Generate JWT" — processing happens in your browser
- 3Copy or download the result
What to do next
About JWT Generator
JWT Generator runs the web and productivity utility job locally inside your browser. Generate JWT tokens with custom claims, expiry, and algorithm selection for testing and prototyping. The work happens on your machine, the result is generated on your machine, and the page exposes the controls you need to drive it without burying them in menus.
From a technical standpoint, JWT Generator is JavaScript and standard browser APIs running in your tab. The browser is the runtime; the page is the interface. Maximum input size: 0 MB per run.
JWT Generator is a static page plus a client-side engine. The browser does the work; there is no separate backend in the loop for the actual processing. That architecture is why the tool starts immediately, why it does not depend on the load on a remote service, and why running multiple jobs in a row does not slow it down.
The heaviest users of JWT Generator tend to be product managers comparing options, creators experimenting with formats and analysts pulling lightweight reports. Each group brings slightly different expectations to the tool, but the same single-page architecture serves every one of them with the same response time.
Reach for JWT Generator when you need a predictable result on a single file. The page works on the first visit, the controls are visible without a menu, and the output is delivered the moment the engine finishes.
The architecture imposes only the limits the browser itself imposes. The published 0 MB ceiling is conservative; most modern devices comfortably handle inputs up to that size, and the cap exists so the tool degrades gracefully on phones and budget laptops rather than running out of memory.
As a workflow component, JWT Generator is the part you reach for when a single, well-defined web and productivity utility step needs to happen. It performs that step and returns a standard file you can carry into the next part of your pipeline.
JWT Generator is built around steady iteration on a small set of options rather than feature creep. Every additional setting attracts a slightly different audience, but a long settings panel makes the common case slower for everyone. The current controls reflect what users of the tool actually use.
JWT Generator returns the result as a download. If you are running multiple jobs, the output names will not collide as long as the input names differ. You can re-run with different settings as many times as you like; each run produces a fresh file with no caching trickery in between.
Some context on why JWT Generator exists in this form: modern File APIs, high-performance JavaScript engines, and well-maintained open-source libraries now make it possible to perform web and productivity utility work entirely in the browser. JWT Generator is built on top of that capability, which is why a single page can host the full pipeline.
If you also use a command-line tool for jwt generator, JWT Generator is a convenient alternative for the times you are on a different machine or helping someone who is not comfortable in a terminal. The output is a standard file in the format documented above.
If you want to get the most out of JWT Generator, three small habits help. Drag-and-drop is faster than the file picker once you get used to it. The keyboard shortcut for downloading the result is whatever your browser uses for "save link as," because the result is a normal download. And if you are working on a sensitive file, processing in an Incognito or Private window is a good extra layer — it leaves no trace in browser history when the tab closes.
When something goes wrong, the cause is usually one of three things: a malformed input, a browser that is out of memory, or a corporate proxy that is interfering with the page's static assets. The first two are easy to diagnose; the third typically requires asking your IT team to allow standard browser APIs to load.
Open the workspace above to start using JWT Generator. The engine loads on the first interaction so the page itself stays light, and once the tool is warm it processes subsequent jobs quickly. The moment the page is interactive, the tool is ready to do real work on your file.
How it works
- 1Open the JWT Generator workspace above. The interface is a single page, so there is nothing to navigate.
- 2Select the web utility file you want to process — drag-and-drop and the file picker both work.
- 3Pick any non-default settings you need. Most users leave the defaults alone for the first run and only revisit if the result needs tuning.
- 4Trigger processing. standard browser APIs reads your input, applies the transformation, and writes the result back into the page.
- 5Download the result. The file is generated in your browser and saved through your normal download flow.
- 6Repeat the process for additional inputs whenever you need to. The page stays loaded, so subsequent runs are quick.
Common use cases
- Run a fast accessibility check before publishing using JWT Generator.
- Plan content without paying for a SaaS dashboard.
- Sanity-check a webhook response while debugging.
- Create a placeholder image for a wireframe.
- Pull a quick reference number for a status update.
- Audit a marketing page before launch.
- Generate a campaign asset in seconds for a quick test.
- Validate a setting before circulating it to a team.
- Preview how a result looks before deploying it.
FAQ
Is the token signed?
No — the token uses a placeholder signature. For production, sign with a real secret on your server.
Can I use this in production?
This is for testing and prototyping only. Production JWTs must be signed with a secret key.
Custom claims?
Add any custom claims as a JSON object. They are merged into the payload.
Private?
Yes — tokens are generated locally.
Expiry?
Set expiry in hours from now. The exp claim is set as a Unix timestamp.
Algorithm?
The algorithm header is set for display purposes. Actual signing requires server-side implementation.
Can I call JWT Generator from a script?
JWT Generator is a browser-only tool by design and does not expose a hosted API. The reason is the same as the privacy story: there is no Favtoo backend doing the work, so there is no service to call. If you need to script the same transformation, the underlying engine (standard browser APIs) is open-source and can be used directly from your own code.
What input formats are supported by JWT Generator?
The accepted formats are listed in the upload area on the tool itself. If your input is in a format that is not directly supported, convert it first using one of Favtoo's converter tools — every Favtoo converter outputs a file that is a clean input to the next tool in the chain.
Are jobs run with JWT Generator stored anywhere?
Favtoo keeps no copy of your file because Favtoo never receives your file. JWT Generator runs entirely in your browser, the input is held only in your tab's memory, and closing the tab discards it. There is no opt-in cloud history, no "recent jobs" panel synced to an account, and no server-side retention to configure — the architecture simply has nowhere for your file to be stored.
Does JWT Generator work with screen readers?
JWT Generator uses native HTML controls wherever possible, which means keyboard navigation, focus rings, and screen-reader labels work the way the platform expects. The drop zone accepts files via the keyboard-accessible file picker as well as drag-and-drop, and result downloads use standard browser download flows. If you spot an accessibility gap, Favtoo treats it as a bug worth fixing.
Is JWT Generator lossless?
JWT Generator is built to preserve quality wherever the underlying web utility format allows it. Operations that are mathematically lossless (e.g. structural transformations, lossless re-encoding) round-trip with no perceptible change. Operations that involve a lossy codec inevitably introduce small artefacts at the byte level, but the defaults aim at the sweet spot where output looks or sounds the same to a normal viewer or listener while still being meaningfully smaller or faster than the input.
Does JWT Generator ask for any browser permissions?
JWT Generator only needs the standard web platform — file picker access for the inputs you choose to load, and optionally clipboard access if you copy the result rather than downloading it. There is no microphone, camera, geolocation or background-permission request, because none of those are needed for the work the tool does.
What is the maximum file size for JWT Generator?
Inputs are capped at 0 MB per file, which keeps memory usage stable across phones, tablets and older laptops. You can run JWT Generator as often as you need; every run produces a full-quality result.
Does JWT Generator work in Safari, Firefox, Chrome and Edge?
JWT Generator works in any modern browser released in the last few years — Chrome, Edge, Firefox, Safari, Brave, Arc and the major Chromium derivatives are all supported. The underlying engine relies on widely-supported web APIs, so there is nothing exotic to install. If you are on a very old browser version and the tool fails to load, updating to the latest release of your preferred browser is the only fix needed.
Can I self-host JWT Generator for my team?
JWT Generator is a static page running an open-source engine in your browser, so a typical corporate firewall does not get in the way as long as it allows JavaScript to load from Favtoo. For teams that need to host it themselves on an internal network, the underlying engine (standard browser APIs) is open-source and can be packaged into a private build with the same behaviour. Reach out via the Contact page if that is something you are exploring.