Developer tools that run entirely in your browser
Eighteen everyday utilities for developers - formatting JSON, decoding a JWT, hashing a file, reading a cron expression - with one rule in common: nothing you paste is ever sent to a server. Open a tool and start working; there is no sign-up, no upload and no usage limit.
JSON & YAML
Encoding & escaping
Security & hashing
Time & scheduling
Text & regex
Generators
Cron expression library
Ready-made explanations for the schedules people search for most.
Why use these tools
Your data never leaves the browser
Every tool here is client-side JavaScript. Paste a production JWT, an API key, a customer record or an internal config file and none of it is uploaded, logged or stored - there is no server on the other end to receive it. Open your browser's network tab and you will see no request go out while you work.
No sign-up, no limits, no waiting
There is nothing to install and no account to create. Pages are static and load in well under a second, tools run instantly on inputs of any size, and everything keeps working offline once a page has loaded.
Explanations, not just output
A JWT decoder that flags an expired token, a cron parser that reads a schedule aloud and shows the next five runs, a JSON formatter that names the line and column of a syntax error. The goal is to answer the question you actually had, not just transform a string.
Frequently asked questions
Are the tools really free?
Yes. Every tool is free with no account, no usage limit and no paid tier. The site is a static site on a free hosting plan, which costs almost nothing to run, so there is nothing to charge for.
Is it safe to paste a real token or secret?
Safer than any server-side alternative. The pages contain no code that sends your input anywhere - no analytics on the input, no logging, no API call. You can verify this yourself in the browser's network tab, or load a page and then disconnect from the network: everything still works.
Do the tools work offline?
Yes, once a page has loaded. The tools are plain JavaScript with no runtime network calls, so they keep working on a plane or behind a firewall. Reloading the page needs a connection unless your browser has cached it.
Which browsers are supported?
Any current version of Chrome, Edge, Firefox or Safari, on desktop and mobile. Hashing and password generation need WebCrypto, which every modern browser provides over HTTPS.