Every developer accumulates a mental list of "things I'll build a script for someday." Most of the time, someone's already built it, and it's one tab away. Here are ten that are worth bookmarking today.
1. JSON Formatter
Pasting a minified API response into your editor and squinting at it is a waste of a good afternoon. The JSON Formatter validates and pretty-prints JSON instantly, and flags the exact line a syntax error is hiding on — which is usually faster than tracing it through your own code.
2. Base64 Encoder / Decoder
Whether you're debugging a JWT payload, decoding a data URI, or encoding credentials for a basic auth header, the Base64 Encoder / Decoder does it in your browser without shipping the string anywhere.
3. Regex Tester
Regex is easy to write and hard to trust. The Regex Tester highlights every match live as you type your pattern, so you catch the edge case that breaks it before it ships, not after.
4. UUID Generator
Need a batch of v4 UUIDs for seed data or test fixtures? The UUID Generator produces them in bulk instead of you writing a one-line script for the fifth time this month.
5. Hash Generator
Verifying a download, hashing a password for a quick prototype, or just checking that two files are byte-identical — the Hash Generator covers MD5, SHA-1, SHA-256, and SHA-512.
6. JS Minifier
For a quick one-off script you're inlining somewhere and don't want to wire into a build pipeline, the JS Minifier strips whitespace and comments without touching your string literals.
7. WHOIS Lookup
Debugging DNS, checking who owns a domain, or confirming when a registration expires — the WHOIS Lookup pulls registrar, dates, and nameserver data in one request.
The pattern
None of these are complicated tools. That's the point — they're the ten-second utilities that add up to real friction over a week, and having them bookmarked means you never have to context-switch into "write a throwaway script" mode for something this small.