Image & Video Quality Comparison

Compare two images or videos with a slider or split view. Synced zoom, pan and playback. 100% local, no uploads.

🔍 A truly local quality-comparison tool — your media never leaves your device. Zero privacy risk. Drop in two images or videos, then compare with a slider reveal or side-by-side split. Zoom, pan, and playback stay perfectly in sync, so you can see the real difference between compression settings, encoder options, or model versions at a glance. 【FEATURES】 ✦ Local & Offline Everything runs right in your browser. No files are uploaded to any server. Works entirely offline. Your footage and artwork stay private. ✦ Two Compare Modes, One Click Apart • Slider reveal: drag the divider to overlay both files at the exact same spot — best for hunting fine detail • Split view: both files side by side for an instant overall read Your last used mode is remembered for next time. ✦ Perfectly Synced Zoom & Pan Both files share a single transform, so no matter how far you zoom or pan, the two sides always show the same region — true pixel-level comparison. Wheel zoom auto-detects trackpad vs. mouse sensitivity, plus pinch-to-zoom, zoom buttons, double-click for 1:1 original pixels, and one-click fit to view. ✦ Dual Video Sync Playback Two videos share one timeline: play, pause, and seek apply to both, with continuous drift correction (50 ms tolerance) so the left and right always show the same moment. Includes 0.25x–2x playback speed, looping, and an audio source switch between muted / A / B. ✦ Mixed Image + Video Comparison Compare a video frame against an exported still: the video plays on the shared timeline while the image stays put. ✦ File Info & Size Delta See format, file size, original resolution, and video duration at a glance — plus B's size difference relative to A as a percentage (e.g. −62%). Hide the info badges anytime to keep the view clean. ✦ Thoughtful Touches Drop two files at once and both A / B slots fill automatically. Swap A / B to inspect from the other direction. Space to play or pause, Esc to exit the full-screen comparison. ✦ Broad Format Support Images: PNG, JPG and popular image formats Videos: MP4, WebM (playback depends on your browser's codec support) ✦ Dark Mode & Bilingual UI Switch between light and dark themes. The interface follows your browser language (English / 简体中文). Easy on the eyes during long detail hunts. 【USE CASES】 • Compression review: confirm whether quality loss after compressing images or video is acceptable • Encoder tuning: compare bitrates, CRF values, resolutions, and codecs on real frames • AI generation & upscaling: evaluate model versions, upscalers, and restoration before/after • Design & photo retouching: spot differences between revisions or export formats fast • Screenshots & UI regression: diff two captures to locate visual changes --- Questions or feedback? Reach us via the email button on the extension page.