glunty Color quantization
Quantization reduces an image from potentially millions of colors down to a small representative palette.
It is how tools extract a dominant palette and how formats like GIF and indexed PNG shrink file size.
Image and color tools
8 tools in this category. Each runs in your browser.
Image and color tools treat pixels as data: extract dominant colors from a photograph, render an image as ASCII art for a chat or a code comment, get AI-generated descriptive names for a palette, write WCAG-aligned alt text for accessibility.
Color extraction quantizes pixels into a small number of distinct hex codes you can paste straight into CSS. The semantic-naming variant adds short descriptive labels generated by AI, useful when writing a brief or naming CSS variables. The hex codes come from your browser; only the abstracted color values leave your machine for the naming pass, which keeps the actual image private.
ASCII art uses a brightness ramp: dark pixels become dense characters, light pixels become sparse characters. The rendering is grayscale by definition. Useful for chat, email signatures, code comments, terminal banners, and quick low-resolution previews of how an image reads at small sizes (the favicon test).
Alt text generation looks at the image plus optional context (article topic, page purpose) and produces a one-or-two-sentence description suitable for the alt attribute. WCAG-aligned: no "image of" prefix, no speculation about emotions, and decorative images get flagged so you know to use empty alt.
The tools share a privacy model: most processing happens in your browser; AI-augmented tools forward only what they need, in a way that keeps your image content local where possible.
Key concepts
The ideas behind these tools, in plain English.
Perceived brightness
Perceived brightness, or luminance, weights green most and blue least because the human eye is far more sensitive to green light.
Averaging raw RGB misjudges which colors read as light or dark, so luminance is what actually decides legible text pairings.
Accessible alt text
Alt text is a concise written description of an image that conveys its purpose to screen readers and to anyone when the image fails to load.
It is essential for blind users and for SEO, and decorative images should use empty alt text so they are skipped rather than announced.
Contrast ratio and WCAG
Contrast ratio measures the luminance difference between text and its background on a scale from 1 to 21, with WCAG requiring at least 4.5 to 1 for normal text.
Meeting the threshold keeps text readable for low-vision users and is often a legal accessibility requirement.
All 8 tools in this category
Compress image (reduce file size)
Shrink a JPG, PNG, or WebP in your browser; adjust quality and resize.
Beautify a screenshot (add a background)
Put a screenshot on a gradient background with padding, rounded corners, and a shadow.
Image to ASCII art
Adjustable width and density.
Color palette extractor
Dominant colors as hex plus CSS variables.
Color palette with AI names
Hex codes + descriptive names.
Alt text generator (AI)
Accessibility-focused alt text from any image.
Color contrast checker (WCAG)
WCAG contrast ratio with AA and AAA pass/fail for text and background.
CSS gradient generator
Linear and radial gradients with live preview and copyable CSS.