10 tools in this collection
Developer Tools
Small, sharp utilities for the tasks you hit every single week.
Developer work is full of tiny, repetitive tasks: reading a mangled JSON payload from a log, decoding a JWT that a colleague pasted into chat, checking what a Unix timestamp actually means, or confirming that a regular expression matches what you think it matches. These jobs are too small for a script and too annoying to do by hand.
Every tool on this page runs entirely inside your browser. There is no upload step, no queue and no account. You paste input, you get a result, and the data never leaves your machine. Each tool page also documents what the tool does, where it can go wrong, and how to verify the output yourself.
Format & Validate
Turn unreadable payloads into something a human can review, and find the exact character that broke them.
Encode & Decode
Move safely between transport encodings and inspect tokens without sending them anywhere.
Base64 Encoder / Decoder
Encode and decode Base64 with correct UTF-8 and URL-safe variants.
URL Encoder / Decoder
Percent-encode URLs and break query strings into a readable table.
JWT Decoder
Inspect JWT header and claims, including expiry and audience.
Generate & Convert
Produce identifiers and convert between human and machine time formats.
Test & Inspect
Check behaviour before it reaches production.
How these tools are chosen
- Deterministic output: the same input always produces the same result.
- Client-side by default, so sensitive data does not need to leave your machine.
- Explicit errors instead of silent failures: if input is invalid, you get the position and the reason.
- Copy-friendly output: results are plain text you can paste straight into a file, issue or chat message.
- No feature bloat: one job per page, documented in plain language.
Developer Tools FAQ
Are these developer tools free to use?
Yes. Every tool on TLKS is free, requires no account, and has no usage counter applied to client-side utilities.
Is my data uploaded to a server?
No. Formatting, encoding, hashing and parsing all happen in your browser using standard platform APIs. You can confirm this by opening your browser network panel while using a tool.
Which tool should I use for a broken JSON payload?
Start with the JSON Formatter. It reports the line and column of the first syntax error, which is usually enough to find the trailing comma or unescaped quote.
Do the tools work offline?
Yes, once the page has loaded, the client-side utilities keep working without a network connection.