How to Compare Images Pixel by Pixel
Use PNG screenshots with matching dimensions when checking a UI change. The image diff highlights pixel differences so you can inspect the affected region.
FileCompare processes supported inputs in the browser, so the content stays on your device. Open the Compare Image tool when you are ready to compare two real versions.
Steps
- Upload the original screenshot.
- Upload the revised screenshot.
- Align canvas sizes and choose split, fade, highlight, or subtract view.
- Review the difference and export the result when needed.
What to Check
- Use the same viewport, device scale, and font-loading state.
- Expect JPEG compression and anti-aliasing to create noise.
- Check transparent pixels when a large region appears different.
When This Workflow Helps
This workflow is useful before a deployment, document handoff, content publication, data import, or QA sign-off. It gives reviewers a compact record of what changed without requiring a desktop suite or command-line setup. For structured formats, review the semantic meaning of the changes after the visual diff; for text formats, confirm that formatting noise is not hiding the important edit.
Limits
Pixel comparison does not understand UI semantics and is not forensic photo analysis. Same-size inputs produce the clearest result.
Try the Tool
Start with a small sample so you can confirm the comparison mode and output before opening a large file. Open Compare Image.
