A design file specifies hex, the component library expects rgb, and a theming layer wants hsl so it can shift lightness programmatically.
- Free
- No signup
- Fast
- Privacy-friendly
Back to Category
Developer tools
Color Converter
Color
Free · API · MCPToolYour platform
Use Color Converter three ways
The free Color Converter on this page works in your browser. The same workflow is available via REST API for apps and via MCP for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the developer-apis module under Developer Tools.
- Free in browserUse Color Converter here — no account required.
- REST APICall from your server with
X-Api-Key. - MCP for agentsConnect Cursor or Claude to ToolYour MCP with the same key.
- 1. Get an API keySign in and open Dashboard → API Keys (works for REST and MCP).
- 2. Call or connectUse the REST API from your server, or paste the MCP URL into your agent config.
- 3. Same qualityOutput matches the free web tool across all three surfaces.
What is Color Converter?
A design file specifies hex, the component library expects rgb, and a theming layer wants hsl so it can shift lightness programmatically. This colour converter accepts any of hex in three, six, or eight digits, rgb, rgba, hsl, or hsla, and returns all four notations at once with alpha preserved through the conversion.
Working in the right notation makes real work easier: hsl lets you build a tint scale by changing one lightness number instead of guessing new hex values, while rgba is what you need for a translucent overlay. The scope is these four sRGB notations — named CSS colours such as rebeccapurple are not accepted as input, and modern wide-gamut spaces including oklch, lab, and colour profile handling are out of scope. There is also no contrast checking here, so accessibility ratios need a dedicated tool. For the stylesheet the values end up in, CSS Formatter keeps it readable.
Browser use is free and needs no signup. The same job runs over REST at POST https://api.toolyour.com/api/v1/developer-apis/color-converter and over MCP at https://api.toolyour.com/mcp — one API key, one shared monthly credit pool, 1 credit per successful call.
What are common questions about Color Converter?
Which input formats are accepted?
Hex in 3, 6, or 8 digits, plus rgb, rgba, hsl, and hsla function syntax. Named colours such as tomato are not recognised.
Is alpha preserved?
Yes. An alpha channel from 8-digit hex, rgba, or hsla carries through to the rgba output and to hex where applicable.
Does it check contrast ratios?
No. Accessibility contrast is a separate calculation between two colours — use a dedicated contrast checker for WCAG ratios.
What are the key features of Color Converter?
All four notations at once
One call returns hex, rgb, rgba, and hsl so you can paste whichever the target needs.
Alpha carried through
Transparency survives conversion between 8-digit hex, rgba, and hsla inputs.
Clear rejection of bad input
Unsupported or malformed colour strings return an error rather than a silent black.
How do you use Color Converter?
Paste the colour
Hex from a design file, or an rgb or hsl value from existing CSS.
Read every format
Pick the notation your stylesheet, token file, or component API expects.
Copy into your tokens
Keep one notation canonical across the design system to avoid drift.
Choosing a notation on purpose
Each format is good at something different. Hex is compact and universal, which is why design tools default to it, but it is unreadable — nobody can tell that two hex values are the same hue at different lightness. RGB maps directly to how displays work and is easy to compute with. HSL separates hue, saturation, and lightness, which is the only one of the three where a human can predict the result of an edit.
That last property is why theming systems favour hsl. Building a nine-step tint scale means holding hue and saturation constant and stepping lightness, which is one readable number per step rather than nine opaque hex strings.
Keeping design tokens consistent
The common failure in a design system is the same colour appearing in three notations across a codebase, so nobody can tell whether two values are identical without converting them. Pick one canonical notation for stored tokens, convert everything to it once, and let the build emit whatever consumers need.
Converting here is the first step; keeping the resulting stylesheet readable is the second, which is what CSS Formatter is for. If tokens live in a JSON file, JSON Formatter keeps that diffable so a colour change shows up cleanly in review.
Which formatter and utility tools sit in this cluster?
Where do you browse more developer tools tools?
- Developer Tools tools
Browse the full Developer Tools category on ToolYour.
- Marketing Tools tools
Build UTM links, check ads copy limits, QA email subjects, and calculate ROAS/CPC/CTR — free in the browser; R
- Security Tools tools
Check HTTP security headers, TLS, cookies, JWTs, passwords, hashes, and SPF/DKIM/DMARC — free in the browser;
Related tools
developer tools
JS Minifier
Shrink JavaScript with a lightweight comment and whitespace pass, reporting byte counts and a caveat.
Freedeveloper tools
CSS Minifier
Strip comments and whitespace from CSS and report original versus minified byte counts.
Freedeveloper tools
Cron Expression Parser
Parse a cron expression and list the next eight UTC run times so you can sanity-check a schedule.
Freedeveloper tools
Cron Expression Generator
Build a five-field cron expression from schedule fields and preview the next five run times in UTC.
Freedeveloper tools
Regex Generator
Return a vetted regex preset for email, URL, IPv4, UUID, digit, or slug shapes, each with a stated limitation.
Freedeveloper tools
SQL Validator
Flag empty statements, unbalanced parentheses, stacked statements, and missing SQL verbs without a database.
Freedeveloper tools
SQL Formatter
Reformat SQL with keyword casing and clause line breaks so long queries become reviewable.
Freedeveloper tools
JS Formatter
Pretty-print JavaScript with Prettier and the babel parser, surfacing syntax errors instead of hiding them.
Freedeveloper tools
CSS Formatter
Pretty-print CSS with Prettier for readable stylesheets, cleaner diffs, and easier specificity review.
Freedeveloper tools
HTML Formatter
Pretty-print HTML with Prettier so templates and response bodies become readable and reviewable.
Freedeveloper tools
IP Address Tools
Validate and classify IPv4 or IPv6 strings, including private and loopback ranges, with no external lookup.
Freedeveloper tools
User Agent Parser
Parse a User-Agent string into browser, operating system, and device hints for log triage.
Free
Popular in Developer Tools
developer tools
JS Minifier
Shrink JavaScript with a lightweight comment and whitespace pass, reporting byte counts and a caveat.
Freedeveloper tools
CSS Minifier
Strip comments and whitespace from CSS and report original versus minified byte counts.
Freedeveloper tools
Cron Expression Parser
Parse a cron expression and list the next eight UTC run times so you can sanity-check a schedule.
Freedeveloper tools
Cron Expression Generator
Build a five-field cron expression from schedule fields and preview the next five run times in UTC.
Freedeveloper tools
Regex Generator
Return a vetted regex preset for email, URL, IPv4, UUID, digit, or slug shapes, each with a stated limitation.
Freedeveloper tools
SQL Validator
Flag empty statements, unbalanced parentheses, stacked statements, and missing SQL verbs without a database.
Freedeveloper tools
SQL Formatter
Reformat SQL with keyword casing and clause line breaks so long queries become reviewable.
Free