How It Works — Three Steps, Two People, One Link
- Upload & Mark the Edit — Upload your original and edited image or PDF. Draw a rectangle over the redacted area. Takes 30 seconds.
- Get a Certificate Link — SealZero checks every pixel outside your selection is unchanged and creates a tamper-proof certificate link you can share.
- Editor Gets Instant Proof — The newsroom opens the link, uploads the image or PDF they received, and confirms it matches the certificate. Done.
Why SealZero?
Not another watermark. Not a metadata tag. A cryptographic proof.
- The original stays private — Your unredacted image never leaves your device. The certificate proves authenticity without revealing what was hidden.
- Ready in under a minute — No installation, no account, no waiting. Open sealzero.dev and start. The certificate link is ready to share in seconds.
- Tied to your identity — Your name is embedded in the certificate. The editor sees who ran the verification and when — a clear chain of custody.
Who Uses SealZero
Anyone who edits images or PDFs and needs to prove the edit is honest.
- Photojournalists — Redact a source's face for safety. The newsroom confirms the rest of the photo is untouched — without ever seeing the unredacted original.
- Legal & Compliance — Blur licence plates or faces in images and PDF documents. Prove the redaction is the only change made — without exposing the full document.
- Research & Medical — Anonymise patient data in medical images. Peer reviewers confirm the clinical content is unaltered before publication.
Frequently Asked Questions
Are my images and PDFs uploaded to a server?
No. All processing happens entirely in your browser. No images or PDFs ever leave your device.
Does the reporter need to share the original image?
No. The original never leaves the reporter's device. The editorial office receives only the edited image and a verification certificate link.
Is SealZero better than a watermark?
Yes. Watermarks can be cropped out and metadata can be stripped. SealZero creates a cryptographic proof tied to the actual pixel content — it cannot be forged without changing the image itself.
Is SealZero free?
Yes. Completely free. No registration, no account. Open sealzero.dev and start immediately.
Ready to Verify Your First Image or PDF?
Takes less than a minute. Free. No account needed. Supports JPG, PNG, WEBP and PDF.