CSS Colors, HEX & Frontend Converters

Convert HSL to HEX, estimate viewport ratios, and generate CSS colors.

All Tools

Choose from our collection of free, accurate tools

BMI Calculator

The Number That Started a Thousand Arguments Walk into any doctor's office in America and within minutes some…

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Tip Calculator

How a Restaurant Consulting Firm Standardized Tip Calculations Across 14 Locations When Meridian Hospitality …

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Fuel Efficiency Converter

What Is a Fuel Efficiency Converter and Why Do You Actually Need One? If you've ever rented a car in Europe a…

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Shoe Size Converter

Why Shoe Sizes Are a Global Mess — And How a Converter Actually Fixes It If you've ever ordered shoes from a …

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Cooking Converter

Why Kitchen Math Keeps Tripping Us Up You're halfway through a recipe that calls for 3 fluid ounces of heavy …

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Fraction to Decimal

What Exactly Does a Fraction to Decimal Tool Do? A Fraction to Decimal converter takes any fraction you throw…

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Percentage Calculator

Why a Percentage Calculator Is the Unsung Hero of Everyday Math Let's be honest — most of us hit a wall the m…

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Binary Converter

Binary Converter: The Essential Tool for Working Between Number Systems Every programmer eventually hits the …

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Roman Numeral Converter

What Is a Roman Numeral Converter — And Why Would You Actually Need One? Most people encounter Roman numerals…

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Number to Words

The Night the Numbers Refused to Speak Marcus had been staring at the same invoice for forty minutes. A freel…

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Number Base Converter

Convert numbers instantly between binary, octal, decimal, and hexadecimal with a live digit-by-digit position…

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Hex to RGB Converter

Paste any hex color code — 3-digit, 6-digit, or 8-digit with alpha — and instantly get the RGB, RGBA values p…

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RGB to Hex Converter

Convert any RGB color value to its hex code instantly. Use sliders or number inputs for R, G, B — see a live …

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Unix Timestamp Converter

Convert Unix epoch timestamps (seconds or milliseconds) to human-readable dates across any time zone, and con…

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Binary to Decimal Converter

Type any binary string and instantly see its decimal value along with a step-by-step place-value expansion th…

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Decimal to Hex Converter

Instantly convert any decimal integer to hexadecimal — with optional 0x prefix, nibble grouping, and negative…

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HSL to Hex Converter

Convert any HSL color — hue, saturation, and lightness — into its hex code and RGB values instantly, with a l…

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Color Format Converter

Paste any color in HEX, RGB, HSL, or HSV format and instantly get all four representations at once — no libra…

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ISO 8601 Date Converter

Convert ISO 8601 date strings, Unix timestamps, and local datetime values instantly — with full timezone offs…

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Timezone Timestamp Converter

Convert any Unix timestamp or ISO date instantly across 25+ world time zones — all results shown side by side…

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Hex to Binary Converter

Convert hexadecimal values to binary with clean nibble grouping — each hex digit maps to exactly 4 bits, maki…

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Color Contrast Checker

Pick foreground and background colors to instantly calculate the WCAG contrast ratio and see AA/AAA pass-fail…

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Built for the moment between a design file and a stylesheet

There is a specific gap in every front-end workflow: you have a color in one format and your code wants it in another. The design comp hands you a hex value, but your CSS custom property is written in RGB. A brand guideline lists an HSL triplet, yet your accessibility audit needs a raw hex to plug into a contrast formula. MiniConvert was shaped around that gap. Instead of hunting through a design app's color picker or opening a bloated online suite, you land on a single card, paste the value, and read back every representation you need — with a live swatch sitting right next to the numbers so your eyes confirm what the math says.

The color tools here — Hex to RGB, RGB to Hex, HSL to Hex, and the all-in-one Color Format Converter — were tuned for people who actually ship interfaces. The Hex to RGB converter accepts three-digit shorthand, full six-digit codes, and eight-digit hex with an alpha channel, so a translucent overlay like #00000080 resolves cleanly to an RGBA string you can drop straight into a shadow or a scrim. RGB to Hex works the other way with sliders and number fields, updating a preview swatch as you drag, which makes it genuinely useful for nudging a token half a step lighter. The Color Format Converter is the one to bookmark when you are documenting a palette: give it any HEX, RGB, HSL, or HSV value and it returns all four at once, no library and no round-trip to a heavier editor.

Accessibility is a conversion problem too

Contrast is where good-looking palettes quietly fail. A muted grey caption on a soft off-white background can look elegant in a mockup and still be unreadable for a large share of your visitors. The Color Contrast Checker treats this as the measurable thing it is: pick a foreground and a background, and it calculates the WCAG contrast ratio and shows you the AA and AAA pass-or-fail verdicts for both normal and large text. That turns a vague "does this feel readable" instinct into a number you can defend in a design review or a pull request. Pair it with the color converters and you have a tidy loop — sample a hex from your palette, check its contrast against your surface color, and if it fails, open HSL to Hex, lift the lightness a few points, and re-test. The whole cycle takes seconds and it is far more reliable than squinting at a screen at full brightness and hoping.

This matters more than it used to. Accessibility requirements are showing up in procurement checklists, government tenders, and app-store guidance, and "we didn't know the ratio" is no longer a comfortable answer. Designers who bake a contrast check into their color-selection habit produce work that survives audits without a painful retrofit later. The point of having the checker sit beside the converters is exactly that — so the accessible choice is the convenient one, not an extra chore you postpone until the end of the project.

Number systems, bytes, and the values that live under the surface

Front-end work is not only color. The moment you touch bitwise flags, canvas pixel data, hardware APIs, or a byte you copied out of dev-tools, you are back in the world of number bases — and MiniConvert covers that tier just as carefully. The Number Base Converter moves any value between binary, octal, decimal, and hexadecimal with a live digit-by-digit position breakdown, so you can see why 0xFF is 255 rather than just being told so. The focused converters — Binary to Decimal, Decimal to Hex, and Hex to Binary — each add their own touch: place-value expansions that teach as they compute, optional 0x prefixes and nibble grouping for readable output, and clean four-bit mapping that makes the relationship between hex and binary obvious at a glance.

That hex-to-binary clarity is quietly the most useful trick on the site for anyone debugging low-level values, because every hex digit maps to exactly four bits with no exceptions. Once that clicks, reading a color's alpha byte, a permission mask, or a raw memory dump stops feeling like guesswork. The Roman Numeral Converter and Number to Words sit alongside for the odd copy or invoice job, but the base tools are the workhorses — the ones you reopen every time a value refuses to make sense in the format your code handed you.

Time, timestamps, and shipping without surprises

The last cluster is about time, and it exists because dates break builds. An API returns a Unix epoch in seconds; your logging system expects milliseconds; a teammate in another timezone reads your "3 PM" as their own. The Unix Timestamp Converter turns epoch values in seconds or milliseconds into human-readable dates across any timezone and converts back the other way, which is exactly what you need when you are staring at a raw number in a database row. The ISO 8601 Date Converter handles the format that machines actually agree on, translating between ISO strings, Unix timestamps, and local datetime values with full offset handling, and the Timezone Timestamp Converter lays a single moment out across more than twenty-five zones side by side so scheduling a launch or a maintenance window stops being a source of quiet dread.

Taken together, these tools are less a "collection" and more a bench of instruments for the same trade: turning a value from the shape it arrived in into the shape your work needs. Everything runs in the browser, nothing is stored, and there is no sign-up between you and the answer. Whether you are matching a brand color, defending a contrast ratio, decoding a byte, or untangling a timestamp, the aim is the same — get you back to building with the right number in your clipboard and no doubt about whether it is correct. That is the whole promise, and the reason designers and front-end developers keep the tabs open.

Why People Choose Web Design Colors

Simple

A clean, distraction-free way to get things done.

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100% Free

No paywalls and no premium tiers — just useful tools.

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Accurate

Trusted formulas you can rely on for real decisions.

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Browser-Based

Nothing to install — it works right in your browser.

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