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Free Design & Developer Utilities

Colour pickers, palette and gradient generators, a regex tester, and a code minifier and beautifier — all running locally in your browser.

5 tools planned in this category — none built yet.

Small utilities that would otherwise cost a context switch: picking a colour and getting a usable palette out of it, converting between HEX and HSL, building a gradient visually instead of guessing at the CSS, checking a regular expression against real sample text, and minifying or reformatting a file.

Developer tools are worth being particular about, because pasted code so often contains something that should not be shared. Nothing you paste here is transmitted.

Planned

Scheduled, not yet built. Nothing here links anywhere — no dead ends.

Coming soon

Colour Picker & Palette Generator

Pick a colour and generate complementary, analogous and triadic palettes from it.

Coming soon

Colour Code Converter

Convert a colour between HEX, RGB and HSL notation.

Coming soon

CSS Gradient Generator

Build a gradient visually and copy the ready-to-paste CSS straight out of the preview.

Coming soon

Regex Tester

Test a regular expression against sample text with live match highlighting and an explanation.

Coming soon

Minifier & Beautifier

Minify or pretty-print CSS, JavaScript and HTML.

What these tools cover

Colour picking with complementary and analogous palette generation, HEX/RGB/HSL conversion, a visual CSS gradient builder with copyable output, live regex match highlighting with an explanation of the pattern, and minification or beautification of CSS, JavaScript and HTML.

Running real tooling in the browser

Terser, the minifier most JavaScript build pipelines use, is itself written in JavaScript, so it runs in a browser tab as happily as in Node. The same is true of the regex engine and the colour maths. These are not simplified reimplementations — they are the actual libraries, loaded on demand so a page you are not using does not pay for them.

Frequently asked questions

Is the code I paste in sent anywhere?
No. Minifying, beautifying and regex testing all happen in your browser. That matters more than it sounds for dev tools — pasted code frequently contains internal URLs, credentials or business logic, and none of it is transmitted here.
Is the minifier the same as running a build step?
It uses the same libraries a build pipeline would — Terser for JavaScript and equivalent tooling for CSS and HTML — so the output is comparable for a single file. What it cannot do is bundle, tree-shake across modules, or apply framework-specific optimisations, since those need the whole project rather than one file.
Will minifying break my JavaScript?
Correct code survives minification. What breaks is code relying on things minification legitimately changes: reading Function.prototype.name, depending on a variable name at runtime, or relying on with. Always test minified output before shipping it, and keep the readable original in version control.
Which regex flavour does the tester use?
JavaScript’s own, since it runs in your browser. That is close to PCRE for everyday patterns but differs in places — lookbehind support varies by browser version, and named groups use the (?<name>…) syntax. A pattern that works here may need adjusting for Python, PHP or grep.
Are the colour conversions exact?
HEX and RGB are the same values in different notation, so those conversions are lossless and exact. HSL involves rounding, so converting HEX to HSL and back can shift a value by one unit. Palette generation is a design heuristic rather than a calculation with one correct answer.
Can I use generated gradients and palettes commercially?
Yes. CSS you copy out and colour values you generate are yours to use with no attribution and no licence conditions.

Browse other categories

PDF Tools

Merge, split, compress, rotate and convert PDF files without uploading them to a server.

Image Tools

Compress, resize, crop and convert images right in your browser, with no quality surprises.

Text Tools

Count, clean, format and compare text — from word counts to JSON formatting and diffs.

Converters & Calculators

Everyday unit, date and money maths: unit conversion, age, BMI, loan EMI and more.

Security & Encoding

Generate passwords, hashes, QR codes and barcodes, and encode or decode text safely offline.