# Tamper Check > A tamper check is a forensic analysis that determines whether a document - PDF, image, or scan - has been edited, forged, or generated by AI. TamperCheck.ai runs 130+ tamper checks on every upload and returns a plain-English AUTHENTIC or TAMPERED verdict, plus a region-level breakdown of where edits were detected. **Canonical URL:** https://tampercheck.ai/tamper-check --- ## What a real tamper check actually looks at A tamper check is more than 'does this look fake.' Visual inspection catches less than 20% of sophisticated edits. A real tamper check has to inspect the file structure, the pixels, and the document's internal logic - all at once. **Structural tamper checks** look at PDF object streams, font tables, embedded metadata, and the cross-reference index. Editing tools leave fingerprints here that are invisible when the document is rendered. **Pixel-level tamper checks** use Error Level Analysis (ELA), noise residue mapping, JPEG ghost detection, and compression artifact analysis to find regions of the image that have been altered. Even a perfectly executed Photoshop edit changes the noise profile of the affected region. **Logical tamper checks** verify that the document's content is internally consistent: running balances add up, dates are sequential, totals match line items, MRZ lines match the visible passport fields. ## What TamperCheck detects ### Error Level Analysis (ELA) Recompresses the image at known quality levels and maps the differences. Edited regions show characteristic ELA signatures that untouched regions don't. ### PDF structure inspection Reads the raw PDF objects, font tables, and metadata. Detects incremental updates, embedded editing-tool fingerprints, and structural inconsistencies. ### Running arithmetic verification For statements and invoices, verifies that every running balance, subtotal, tax line, and total is mathematically consistent. ### MRZ & checksum validation For identity documents, validates Machine Readable Zone integrity, checksums, and consistency with visible fields. ### AI-generation detection Detects spectral and noise signatures characteristic of generative AI outputs - the kind of fakes that pass every visual check. ### Producer metadata audit Verifies the document's producer string matches what the issuing organisation would actually use. Mismatches are a strong tamper signal. ## How to run a tamper check with TamperCheck.ai TamperCheck.ai is the fastest way to run a comprehensive tamper check on any document. Upload via the dashboard for a one-off check, or integrate the API to run tamper checks on every document submitted to your workflow. - **Upload any file type** - PDF, JPG, PNG, HEIC, scan - **Verdict in ~1 minute** - AUTHENTIC, TAMPERED, or INCONCLUSIVE - **130+ tamper checks** run automatically - **Region-level findings** - know exactly where the edit is - **Free tier** - no credit card needed for first checks - **API + dashboard** - choose your integration model - **Zero file storage** - tamper checks run ephemerally ## Frequently asked questions ### What is a tamper check? A tamper check is a forensic analysis of a document file - PDF, image, or scan - to determine whether it has been edited, forged, or generated by AI. A complete tamper check inspects the file's internal structure, the pixel-level properties of any images, and the logical consistency of the content (arithmetic, dates, field relationships). ### How do I tamper-check a PDF? Upload the PDF to TamperCheck.ai. The system runs 130+ forensic checks - PDF structure inspection, font metric analysis, metadata audit, pixel-level Error Level Analysis on any embedded images, and arithmetic consistency checks on tabular data - then returns a verdict and a region-level findings report in about a minute. ### Can a tamper check detect AI-generated documents? Yes. AI-generated documents have spectral signatures, noise patterns, and compression artifacts that real scanners and printers don't produce. A modern tamper check includes a generative-AI detection layer trained on these signatures, which catches synthetic documents that pass visual inspection. ### Is there a free tamper check tool? TamperCheck.ai offers a free tier with no credit card required. You can run tamper checks on documents through the dashboard and see the full forensic report. Higher-volume usage is $0.50 per document with no subscription. ### What's the difference between a tamper check and OCR? OCR extracts text from a document; a tamper check verifies that the document is authentic. They solve different problems. Most teams need both: OCR to read the content, and a tamper check to confirm the content hasn't been altered. TamperCheck integrates with any OCR or data extraction layer. ## Related use cases - https://tampercheck.ai/use-cases/kyc-identity-verification - https://tampercheck.ai/use-cases/lending-credit - https://tampercheck.ai/use-cases/insurance-claims ## Compare with alternatives - https://tampercheck.ai/compare/inscribe-vs-tampercheck-ai - https://tampercheck.ai/compare/resistant-ai-vs-tampercheck-ai --- Try TamperCheck free: https://tampercheck.ai/dashboard · Docs: https://tampercheck.ai/docs · Pricing: https://tampercheck.ai/pricing