Summarize the most prevalent visible colors in a WebP as practical HEX and RGB swatches. A bounded decoded sample is quantized into 5-bit RGB buckets, weighted by alpha visibility, ranked by coverage, and written to a portable JSON report.
How to use Color Palette Extractor
- Choose a static WebP whose visible color family needs measurement.
- Select the requested palette length and run the local extraction.
- Review swatches and coverage in design context, then copy values from the JSON into a style guide, placeholder, or audit.
What this tool is good at
When to use Color Palette Extractor
Prepare a deliberate color palette asset
Summarize prominent visible color families for design references, placeholder decisions, content audits, or asset comparisons. Work from the selected WebP's decoded pixels and measured output instead of assuming a filename, generic preset, or browser preview answers the production question.
Compare real local results
Read HEX, RGB, pixel count, and coverage together, then validate color suitability and contrast in the intended interface rather than treating prevalence as meaning. Keep the derivative or JSON report with a content ticket, optimization review, design handoff, or regression fixture so another person can reproduce the decision.
Protect private production imagery
Process unreleased campaigns, product photos, client media, interface assets, and internal fixtures in the current browser tab without submitting selected image bytes to a remote conversion or analysis endpoint.
How to choose the right settings
Match the destination requirement
Summarize prominent visible color families for design references, placeholder decisions, content audits, or asset comparisons. Confirm dimensions, background, alpha behavior, quality budget, analytical resolution, and consuming application before applying the same setting to a larger batch.
Inspect a representative result
Read HEX, RGB, pixel count, and coverage together, then validate color suitability and contrast in the intended interface rather than treating prevalence as meaning. Check detailed and flat-color samples, transparent edges, gradients, text, and varied aspect ratios because one convenient default cannot represent every source.
Retain the authoritative original
Quantization combines nearby colors, full ICC color-management proof is outside browser Canvas, transparent pixels are ignored, spatial arrangement is lost, and animation is rejected. Keep source WebP files until generated assets and reports have been reviewed in the real destination and accepted by the responsible editor or developer.
Practical workflow and output details
A bounded decoded sample is alpha-weighted, grouped into 5-bit RGB buckets, ranked by visible coverage, and serialized as JSON. Processing uses bounded browser Canvas operations, typed-array pixel analysis, local WebP or PNG encoding, and Blob downloads; selected file bytes are never posted for image processing.
Quantization combines nearby colors, full ICC color-management proof is outside browser Canvas, transparent pixels are ignored, spatial arrangement is lost, and animation is rejected. The tool states this boundary so a focused local operation is not mistaken for a color-managed editing suite, universal performance benchmark, perceptual-quality guarantee, animation editor, or reversible source-of-truth workflow.
Format behavior and limitations
Quantization groups nearby colors and the report is not a full list of every unique pixel value or an ICC-managed color proof.
Large images are proportionally sampled to 256 pixels on the longest side, which balances speed with broad color representation.
Frequently asked questions
Why are similar colors combined?
Five-bit quantization groups small channel differences so the palette emphasizes useful dominant families instead of thousands of nearly identical values.
Are transparent pixels counted?
Fully transparent pixels are ignored and partial alpha reduces a color's weight.
Can this choose accessible brand colors?
No. It measures source colors; contrast, semantics, and brand suitability require separate design judgment.
Related WebP tools
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Dominant-Color Placeholder
Find a weighted dominant decoded color and generate CSS placeholder variables with contrast guidance and measured color coverage.
WebP Transparency Checker
Decode every WebP frame and count actual transparent or translucent pixels instead of relying only on an alpha feature flag.