Tampering Detector
Spot edited areas in a JPEG with Error Level Analysis.
What does the tampering detector do?
The freeimgtool tampering detector runs Error Level Analysis (ELA), a classic forensic technique for spotting edits in JPEG images. The idea: a JPEG that has been opened, edited, and re-saved compresses differently in the edited regions than in the original. By re-saving the input at a known quality and measuring the difference, edited regions show up as brighter patches in the result image.
ELA is a heuristic, not a verdict. A bright spot does not prove fakery, and a clean ELA does not prove authenticity. Treat the result as a hint — a starting point for closer inspection.
How to use it
- Click the upload box and pick a JPEG (up to 5 MB).
- Drag the amplification slider. Start around 15. Raise it to see fainter regions, lower it if the whole image is white.
- Click Analyze.
- Inspect the verdict, max/mean error numbers, and the ELA image.
- Optionally download the ELA visualization to compare with the source.
How to read the result
- Uniformly dark with sharp edges visible: consistent compression history — usually a clean original.
- One area noticeably brighter than its surroundings: that area may have been pasted, masked, or edited.
- Entire image is bright: the JPEG has been re-saved many times. ELA loses signal here.
- PNG or WebP input: ELA cannot meaningfully separate edits from compression because there is no JPEG quantization baseline.
Why use this tool
Most photo forensic tools sit behind academic logins or paywalled investigator suites. ELA is the single most useful check a non-expert can run quickly. This tool gives you the slider and the visualization in three clicks with no signup.
Who uses it
Journalists vetting a forwarded photo. Investigators spotting edits in a contract scan. Insurance adjusters checking damage evidence. HR teams reviewing scanned documents. Anyone who wants a fast sanity check before trusting an image.
Frequently asked questions
Does a bright spot mean the photo is fake?
No. It means that area has a different compression history. Edits are one cause, but text overlays, watermark removal, and even some camera processing produce similar signals.
Why does my PNG show very low error?
PNG is lossless. ELA depends on JPEG quantization artifacts and cannot draw conclusions from a PNG. Convert your image to JPEG only if you want a baseline — the result is still indicative, not authoritative.
Why does an unedited photo light up at the edges?
JPEG compression always produces higher error along high-contrast edges. As long as the brightness is uniform across all edges, that is normal and not a sign of tampering.
What amplification should I use?
15 is a sensible default. Try 25 for very high-quality JPEGs where everything looks dark, or 8 for low-quality JPEGs where everything looks blown out.
Is this tool free?
Yes. No signup, no premium tier. Display ads support the site.
What is the maximum upload size?
Five megabytes per image. Compress first with the image compressor if needed.
Is my image stored?
Uploads are kept only long enough to return the ELA image link and are removed automatically. Privacy policy has the details.
Can the result be used as legal evidence?
No. ELA is a non-conclusive heuristic. Legal investigations require chain-of-custody handling and certified forensic tooling, not a free web tool.