AltRepo Labs
Comprehensive tools
Labs is home to our most in-depth, feature-rich tools. Like everything on AltRepo, they run entirely in your browser, so your data never leaves your device.
Color Contrast Checker
WCAG & APCA contrast scoring, palette grids, and live AA/AAA feedback.
ComprehensiveColor Palette Extractor
Pull dominant palettes from any image with export-ready swatches.
ComprehensiveColor Harmony Generator
Build complementary, triadic, and analogous schemes from any base color.
ComprehensiveColor Blindness Simulator
Preview designs through multiple color-vision deficiency models.
ComprehensiveYouTube Thumbnail Preview
See how thumbnails render across YouTube surfaces before you publish.
Comprehensive