Developer Tools: Formatters, Encoders, Generators and Debugging Utilities

Little jobs. The kind I do twenty times a day and never, ever want to open a heavyweight app for. Pretty-print some JSON, or decode a JWT to see why auth keeps rejecting it. Sanity-check a cron line before it pages me at 3 a.m. and ruins a perfectly good night. Honestly, I think most online dev tools overthink this, so here mine just sit, all on one page. You paste something and read the answer. Then you close the tab. It all runs in your browser. Whatever you type stays on your machine.

Text Diff CheckerDrop in two texts and see exactly what changed, line by line or word by word, lined up side by side.Case ConverterFlip text between UPPER, lower, Title, camelCase, snake_case, kebab-case and more. It splits camel boundaries the smart way.Number Base ConverterDecimal, hex, binary and octal all linked live, BigInt-sized. Custom base 2 to 36, with a real two’s-complement view.JSON / CSV ConverterConvert JSON to CSV and back with a real RFC 4180 parser. Quoted fields, embedded commas and newlines all survive the trip.YAML / JSON ConverterConvert YAML to JSON and back, with honest handling of the Norway problem, leading zeros and anchors.JSON FormatterPaste an ugly one-liner. Get it back indented, actually readable. It flags the spot where the JSON breaks, which beats squinting. Minify it again when you’re done.YAML ValidatorIt’s the indentation. It’s almost always the indentation. Drop your YAML in here and I’ll point at the line that’s off, hopefully before your pipeline gets a chance to.XML FormatterFor those days a SOAP response lands as one endless, unbroken line. Or a config dump does. Indent it so you can breathe, then collapse it back down after. It also catches the tag you forgot to close.Base64 Encoder / DecoderEncode a string, or read one back the other way. It handles UTF-8 the way you’d hope. There’s a URL-safe mode too, for when stray padding and slashes would quietly wreck a query string.URL Encoder / DecoderThat wall of %20s and %3D? Turn it back into something a person can read. Encode a single component, or take a messy query string and pull it apart into its pieces.JWT DecoderSplits a token into its header and payload so you can finally see what’s in there and whether it’s already expired. One catch worth saying out loud: it reads the claims but won’t verify the signature. Decoding happens on your machine, never on mine.UUID GeneratorNeed a v4 UUID this second for a test row or some config key? There you go. And if you’ve got a string and you’re not even sure it’s a real UUID, paste it. It’ll tell you.Hash GeneratorDrop in some text, get its SHA digest back. Mostly I reach for it to confirm a download wasn’t tampered with. You match it against the checksum the vendor published. If the two line up, fine. If they don’t, don’t run the thing.Timestamp ConverterThat 1717459200 sitting in your logs, staring back at you. Turn it into a date you can read, or run it the other way. It sorts out seconds versus milliseconds on its own, which is the part I get wrong by hand every single time.Cron Expression GeneratorWhich field is day-of-week again? I never remember. So you just pick when the job should run, it writes the five-field line for you, then says back in plain English when that line fires.Regex TesterWrite a pattern. Throw some sample text at it and watch what lights up, live, as you type. Capture groups get highlighted. You can dry-run a replacement first, before you ever point it at data you can’t get back.Regex GeneratorYou know what you want to match. An email, say, or an IP address. You just can’t face hand-rolling that pattern one more time. It builds one for you, and you can test it right there on the spot.Color ConverterFlip a color from HEX to RGB to HSL and back, no mental math required. It checks the contrast ratio between two colors as well. Maybe it’s just me, but I’d rather know the text fails legibility now than hear about it later.

Developer utilities

It all runs right here in the browser. No upload, no account. Nothing waiting on a server two timezones away. I built them around the work I actually do: chasing a broken API response until it makes sense, or wrestling a config that flat-out refuses to parse. Generating some value I need once and then forget by lunch. If you basically live in a terminal and a text editor (I do), these patch the small gaps those two leave open.

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Sources & further reading

MDN Web Docs