Does the animation start automatically?
No. It starts only after you load both images and select Start animation.
Motion and flashing warning
This tool intentionally alternates images. Rapid visual changes may be uncomfortable or unsafe for people with photosensitive conditions. The animation does not start automatically. Choose a slow interval, stop immediately if uncomfortable, and do not publish flashing output without considering viewer safety and platform accessibility guidance.
Upload before and after photos
Why flicker comparison works
The visual system notices movement. When two aligned images alternate, a changed edge appears to jump even when it is difficult to find in side-by-side views. This can help with retouching review, restoration, repeated landscape photos, document revisions, and basic visual quality checks.
Movement can also exaggerate harmless camera or scaling differences. Verify findings with the overlay tool or a complete side-by-side view before drawing conclusions.
Use flicker responsibly
- Start with a slow interval such as 1.5–3 seconds per image.
- Keep a visible pause control available whenever the animation is shown.
- Avoid strong high-contrast full-screen changes and rapid repetition.
- Do not autoplay flicker content on a public page.
- Provide a static comparison alternative for viewers who avoid animation.
- Label animated content clearly before it starts.
GIF or video?
| Format | Strength | Limitation |
|---|---|---|
| Animated GIF | Simple looping support in many documents and messages | Large files, limited colors, no efficient modern compression |
| Video | Better compression and color for social publishing | Exact format depends on browser recording support |
| Static side by side | No motion concern; both images remain visible | Small differences may be harder to notice |
Flicker comparison questions
What interval should I choose?
Start slowly. One to three seconds per image is usually enough to compare changes without aggressive flashing.
Why do unchanged edges move?
The source photos may differ in crop, scale, perspective, or camera position. Align them before treating movement as a content change.
Why can GIF export be slow?
GIF encoding is CPU-intensive and inefficient for detailed photos. Video is usually smaller and better for photographic animation.