Home/Guides/Tamper Check

Tool

Run a tamper check on any document - PDF, image, or scan.

A tamper check inspects whether a document has been edited, forged, or generated by AI. Visual inspection catches less than 20% of sophisticated edits. TamperCheck looks at the file structure, the pixels, and the document's internal logic - then returns a plain-English authentic, tampered or AI-generated verdict with a region-level breakdown of where edits were detected.

  • No document storage
  • Digital, scanned or photographed
  • ~1 minute per verdict

Last updated:

See it catch this on your documents

A 30-minute call with a live demo on the documents you actually receive.

Which documents should we check? (optional, pick any)

One business day to respond. No sequence, no drip campaign. Just a calendar invite.

The problem

What a tamper check actually inspects

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 we detect

Forensic signals that expose fraud

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.

The solution

Dashboard for one-offs, API for every document

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.

Digital PDFsPhone photosScanned hard copiesPhysical stampsHandwritten signatures

How it works

  • Upload any file type - PDF, JPG, PNG, HEIC, scan
  • Verdict in about a minute - authentic, suspicious, tampered or AI-generated
  • 200+ tamper checks run automatically
  • Region-level findings - know exactly where the edit is
  • First top-up matched free - we double what you start with
  • API + dashboard - choose your integration model
  • Zero file storage - tamper checks run ephemerally

Why us

What you won't get elsewhere

Findings, not a score

We name the field that changed and where it sits on the page.

Others hand you a number to justify.

One endpoint, every type

100+ document types, 190+ countries, no per-type setup.

Elsewhere, each new form is a project.

Catches what was never real

A dedicated pass for AI-generated and deepfake documents.

Template matching only catches edits.

Nothing is retained

Analysed in memory, then discarded. Never trained on.

Most services keep documents for QA.

Live in minutes

Published pricing, no minimum. Test it before you talk to us.

Platforms want a contract first.

Sits alongside your stack

Keep Onfido or Jumio for face match. We add the forensics.

Not a rip-and-replace.

FAQ

Common questions

What is a tamper check?

A forensic analysis of a document file to determine whether it's been edited, forged, or AI-generated. A complete 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 it to TamperCheck.ai. The system runs structural inspection, font metric analysis, metadata audit, pixel-level Error Level Analysis, and arithmetic consistency checks, then returns a verdict and a region-level findings report.

Can a tamper check detect AI-generated documents?

AI-generated documents carry spectral signatures, noise patterns, and compression artifacts that real scanners and printers don't produce. TamperCheck includes a generative-AI detection layer trained on these signatures - it catches synthetic documents that pass every visual check.

What does a tamper check cost?

Per-document pricing, no subscription. New accounts get their first top-up matched with free credits, so you start with double the balance to verify through the dashboard or the API.

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. Different problems, and most teams need both: OCR to read the content, a tamper check to confirm it hasn't been altered.

Related

Keep reading

Or skip the call entirely

We'll match your first top-up in credits, so you can run your own documents through it now.