Compare images and PDFs. Spot the differences.
Find changes in photos, illustrations, drawings and multi-page PDFs. Align two photos or split one spot-the-difference picture, then inspect difference candidates in red. Files are processed on your device.
- ① Choose files
- ② Find differences
- ③ Zoom in and check A/B
Results are candidates. Missed changes and false positives are possible. Check important changes in the original files.
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How to compare images, drawings and PDFs
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Compare two images or phone photos
Put the original image in A and the comparison image in B, then choose Find differences. You can drag and drop both files together. On a phone, select images from your photo library. For photos of the same flat page or surface, the tool attempts to correct perspective and position. If automatic alignment fails, choose four matching points.
Find differences in one side-by-side or top-and-bottom picture
Choose Split one image, select your picture and choose its layout. Adjust the split position to separate A and B, including any gap between the pictures. This mode can help you review spot-the-difference puzzles.
Compare multi-page PDFs and drawing revisions
Choose Two PDFs. Pages are matched using appearance and text, so page numbers can change. Added, removed and substantially different pages are listed under Unmatched pages. Review ambiguous matches before trusting a pair. For drawings, you can adjust horizontal and vertical offsets or select smaller areas at the same scale. PDFs with embedded text also offer a collapsed Compare text section.
Review changes without losing your place
Select a numbered region or tap the image to zoom, then switch between A, B and Overlay. The zoom frame keeps its size as you move between candidates. Choose Show whole image to return.
The expected count is optional. A single large change can produce several regions. Increasing sensitivity or adjusting to a count retains detected evidence, so the number of regions can exceed your guide. Lowering sensitivity runs detection again at that setting. Always check the actual locations in A and B.
Questions and accuracy limits
What if I know the number of differences?
After comparing, enter an optional expected count from 1 to 80. The tool searches for a suitable sensitivity while retaining detected evidence. The number of regions may differ from the expected count. Matching counts do not guarantee correct answers.
Can I compare photos taken with a phone?
Yes. Choose two photos of the same flat surface or scene. Automatic alignment attempts to correct perspective and position. If it fails, select four matching points. Photograph flat pages at similar distances and lighting, avoiding blur and glare. Parallax on 3D objects and bent paper cannot be fully corrected.
Can it find every difference without false positives?
No. These are candidates for review, not verified answers. Compression, blur, shadows, reflections and viewing angles can produce extra regions, and small changes may be missed. Compare each candidate in A and B and check important changes in the originals.
Which formats and file sizes are supported?
Use JPEG, PNG, WebP or another image format supported by your browser, or PDFs. Each file may be up to 25 MB; each PDF may contain up to 60 pages. Image comparison resizes the longest side to at most 1250 pixels; PDF comparison uses up to 4080 pixels. Very small lines or dimension text may be missed. Crop images or select PDF areas to inspect a smaller region.
Can it compare text in scanned PDFs?
Scans can be compared visually, but this tool does not perform OCR. Text comparison requires embedded text in both PDF pages. Text comparison is limited to 1000 lines and 60000 characters.
Are my files uploaded?
Selected files are processed in your browser and are not uploaded to a comparison server. The processing screen is on a separate domain without ads or analytics. Consented usage analytics on the parent page records the type of use, not filenames, file contents or detected locations. Clear files or close the comparison screen to discard loaded data.
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