Image & Video Quality Comparator

🔍 Free image & video comparison tool — compare two images or videos side by side or with a before/after slider. 100% local: your photos, screenshots and footage never leave your device. No upload, no sign-up, zero privacy risk. Drop in two images or videos, then compare with a slider reveal or side-by-side split view. Zoom, pan, and playback stay perfectly in sync, so you can spot the real difference between compression settings, encoder options, export formats, or AI model versions at a glance — a true pixel-level quality checker. 【FEATURES】 ✦ Local & Offline — Private Image Compare Everything runs right in your browser. No files are uploaded to any server. Works entirely offline. Your footage, photos and artwork stay private. ✦ Two Compare Modes, One Click Apart • Before / after slider: drag the divider to overlay both files at the exact same spot — best for hunting fine detail and compression artifacts • Side-by-side split view: both files next to each other for an instant overall read Your last used mode is remembered for next time. ✦ Perfectly Synced Zoom & Pan — Pixel-Level Diff 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-by-pixel image diff. 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 — Video Comparison Tool 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 frame. Includes 0.25x–2x playback speed, looping, and an audio source switch between muted / A / B. Ideal for video quality tests and encoder comparisons. ✦ 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%). Perfect for checking how much space a modern format like WebP saves over a JPEG original. 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 Open all mainstream image formats like PNG and JPEG, plus common video formats such as MP4 (video playback depends on your browser's codec support). ✦ Dark Mode & 12-Language UI Switch between light and dark themes. The interface follows your browser language (English, 简体中文, Español, Português, 日本語, Deutsch, Français, 한국어, Русский, Indonesia, Tiếng Việt, हिन्दी). Easy on the eyes during long detail hunts. 【USE CASES】 • Compression review: check image quality before and after compressing photos — see exactly what compression does to your pictures • Encoder tuning: compare bitrates, CRF values, resolutions, and codecs on real frames • AI generation & upscaling: evaluate before/after results from AI upscalers, image enhancers, restoration and super-resolution models • Design & photo retouching: spot differences between revisions or export formats fast — a visual diff for designers and photographers • Screenshots & UI regression: diff two screenshots to locate visual changes, pixel shifts and rendering bugs • Photo quality check: compare camera originals vs. edited or exported versions pixel by pixel --- Questions or feedback? Reach us via the email button on the extension page.