Developer toolbox · eight tools · no upload
Tools that never see your data
JSON to TypeScript, JWT decoding, cron explanations, regex, text diff, base64, hashing and UUIDs — in one page, with no server behind it. Paste a token or a payload you would not put into a random website; it stays in this tab.
No sign-upNo uploadWorks offline
Pick a tool
Eight utilities, one tab
Straight answers
Questions about the toolbox
- Does anything I paste get sent to a server?
- No. Every tool on the page runs in the browser tab. There is no API route behind it, so pasted tokens, payloads and source files never leave your machine — which also means it is safe for work you would not put in a random web tool.
- How does the JWT decoder work?
- It base64url-decodes the header and payload sections so you can read the claims. It does not verify the signature, because that needs the issuer's key and a secret you should not be pasting into a website. Treat the output as untrusted data.
- Is the TypeScript output type-safe?
- It is a starting point, not a guarantee. Types are inferred from the JSON sample you paste, so fields absent from that sample stay invisible, and nullable values come out as null. Review the interfaces before shipping them.
- Does the cron tool support seconds and special syntax?
- It handles standard five-field cron: minute, hour, day of month, month and day of week, including ranges, lists and steps. Extended Quartz syntax with seconds, L, W and # is not interpreted.
- Why build these instead of using an existing site?
- Because these run offline and keep your data local, and because they are the kind of tool we build for clients. It is also a fair demonstration of the stack: no server, no dependency, no place for your input to leak.
More tools: the full list.