RGB to HEX Converter: Instant Color Code Lookup
Convert RGB color values to HEX color codes instantly.
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Contrast on white & black
WCAG 2.1 contrast ratio of #2563EB against a white and a black surface.
AA needs 4.5:1 for normal text and 3:1 for large text (18pt, or 14pt bold); AAA needs 7:1. Use this to choose white or black text over the color.
About this conversion
RGB and HEX represent the exact same color information in different notation. RGB uses three decimal numbers (0–255 each), while HEX packs the same values into a six-character hexadecimal string preceded by a hash. The conversion is purely mathematical — no color information is gained or lost.
The reason HEX dominates web development is historical: early HTML supported HEX color attributes before CSS existed, and the format stuck. Today, CSS accepts both rgb(37, 99, 235) and #2563EB, but HEX remains the default in most style guides, design tokens, and brand documentation because it is more compact and easier to copy as a single string.
One practical difference matters for developers: HEX does not natively support alpha transparency. If you need a semi-transparent color, you either use the 8-digit HEX format (#2563EB80 for 50% opacity) or switch to rgba(). The 8-digit format works in all modern browsers but breaks in IE11 and some older email clients. For email HTML, stick to 6-digit HEX or named colors.
This tool outputs uppercase 6-digit HEX codes, which is the most widely compatible format. If you also need the CMYK breakdown for print work, the RGB to CMYK converter takes the same input values.
Worked examples
Real conversions this tool produces — enter the inputs to reproduce each result.
Encoding a brand blue for CSS
Input
- Red (R)
- 37
- Green (G)
- 99
- Blue (B)
- 235
Result
- HEX
- #2563EB
Each channel becomes a two-digit hex pair: 37 → 25, 99 → 63, 235 → EB. Read a hex backwards and you can estimate the RGB without a tool — EB is near 255, so this blue is almost maxed.
A pure web orange
Input
- Red (R)
- 255
- Green (G)
- 102
- Blue (B)
- 0
Result
- HEX
- #FF6600
255 → FF and 0 → 00, the two extremes of a hex pair. Any channel at FF is fully on; any at 00 is fully off.
An emerald accent (the site's success colour)
Input
- Red (R)
- 16
- Green (G)
- 185
- Blue (B)
- 129
Result
- HEX
- #10B981
Green dominates at 185 (B9) with a meaningful blue (81) — that blue is what makes it an emerald rather than a grassy green.
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Color conversions are mathematical approximations. For critical color work, verify against physical swatch books and printed proofs. See our methodology and full disclaimer.
Frequently Asked Questions
What is a HEX color code?
A HEX color code is a six-character string (like #FF5733) that represents a color using hexadecimal notation. Each pair of characters encodes the red, green, or blue channel as a value from 00 to FF (0–255 in decimal). HEX codes are the standard way to specify colors in CSS, HTML, SVG, and most design tools.
Is the RGB to HEX conversion lossless?
Yes. Both formats describe the same sRGB color space using different notation. Converting back and forth always produces identical values. The only caveat is rounding: if you start with fractional RGB values (common in color pickers that use percentages), they are rounded to the nearest integer before HEX encoding.
Can I use shorthand HEX codes?
Yes. When each pair of hex digits is identical (e.g., #FF3366), you can shorten it to three characters (#F36). However, this tool always outputs the full six-digit format for maximum compatibility. Note that 8-digit HEX (#RRGGBBAA) for transparency is also valid in modern CSS but not supported in older email clients or IE11.
Should I use HEX or RGB in my CSS?
Both are equally valid in modern CSS. HEX is more compact and widely used in design systems and brand guidelines. RGB is easier to read when you need to understand channel values at a glance or calculate contrast ratios. For programmatic color manipulation (darkening, lightening, mixing), HSL is often more intuitive than either — see our RGB to HSL converter.
Does HEX work for print colors?
HEX and RGB describe screen colors (additive light). Printers use CMYK (subtractive ink). A HEX code defines how a color looks on a monitor, not on paper. To get print-accurate values, convert to CMYK using our RGB to CMYK converter, and be aware that some vivid screen colors cannot be reproduced in ink.
Cite or embed this tool
Cite this tool
PrinterTools. (2026). RGB to HEX Converter: Instant Color Code Lookup [online tool]. https://printertools.net/tools/rgb-to-hexEmbed this tool
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<a href="https://printertools.net/tools/rgb-to-hex" target="_blank" rel="noopener" style="display:inline-flex;align-items:center;gap:8px;padding:10px 14px;border:1px solid #e2e8f0;border-radius:8px;background:#ffffff;font-family:system-ui,-apple-system,sans-serif;font-size:14px;line-height:1.3;color:#2563eb;text-decoration:none;">RGB to HEX Converter: Instant Color Code Lookup — free tool by PrinterTools</a>More Print calculators
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