PDF Validity Checker
Check whether a PDF is genuinely valid and fully readable, or has hidden corruption — page by page, right in your browser.
Drop a PDF here to check if it's valid
How the PDF validity check works
A PDF can look completely normal at a glance and still have problems underneath it — a damaged cross-reference table, one corrupted page buried in a 200-page report, or content that only certain viewers happen to tolerate. This tool runs a real PDF parser against your file directly in your browser: first confirming it starts with a proper PDF header, then parsing the full document structure, then opening every individual page one at a time to catch issues that only surface when a page is actually rendered — with live progress as it works through larger files.
If everything checks out, you get a clear confirmation along with the page count and file size. If something's wrong, you get a specific breakdown instead of a vague error: which pages failed to open, whether the file header itself is malformed, or whether the document couldn't be parsed as a PDF at all. A password-protected file is reported separately from a genuinely corrupted one, since being locked isn't the same problem as being broken. Once a check finishes, you can copy the results or download them as a text report to share elsewhere.
Common use cases
- Verifying a file downloaded or transferred correctly before relying on it for something important
- Diagnosing why a specific PDF fails to open in one application but not another
- Checking a scanned or generated PDF for corruption before archiving it long-term
- Confirming a PDF is genuinely intact before a submission, upload, or client delivery deadline
- Getting a shareable report to send to whoever generated the file, or to a support team
Worth knowing: this checks structural readability, not archival or accessibility conformance — it won't tell you whether a file meets PDF/A or PDF/UA standards, and it can't repair a file it finds damaged. It also can't inspect the contents of a password-protected PDF until it's unlocked. Because the check runs entirely on your device, there's no upload wait and no size restriction beyond what your browser can handle.
Related tools
PDF Validity Checker — frequently asked questions
It confirms the file starts with a valid PDF header, that the document structure can be parsed at all, and then opens every individual page one by one to catch damage that only shows up when a page is actually rendered.
Some corruption only affects specific pages, or is quietly tolerated by lenient viewers that skip over damaged content instead of reporting it. This tool checks every single page and reports exactly which ones failed, rather than a casual open-and-look.
No. That's shown as a separate, amber "can't verify" result rather than a red error, because the file itself isn't necessarily broken — its contents just can't be inspected without the password. Unlock the PDF first (see the Unlock PDF tool) for a full check.
No — it only diagnoses, it doesn't repair. If pages are genuinely damaged, going back to the original source file or a backup copy is usually the most reliable path, since PDF repair often can't recover data that's truly gone.
The results list shows the first several issues with a "show more" option rather than dumping hundreds of entries on screen at once, so a badly damaged file stays readable instead of turning into an unusable wall of text.
Yes — Copy report puts a plain-text summary on your clipboard, and Download report saves it as a .txt file, useful for attaching to a support ticket or sending to whoever built the PDF.
Yes. A Cancel button is available while pages are being checked, so you're not stuck waiting through an enormous file if you picked the wrong one.
No — this checks whether the file is readable and structurally intact, not whether it meets archival (PDF/A) or accessibility (PDF/UA) standards, which are a different, stricter kind of conformance check.
No. The file is read and parsed directly in your browser using a JavaScript PDF library — it's never sent to a server, so this is safe to use on confidential or unreleased documents.