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Repair a damaged PDF

Fix PDFs that won't open or render correctly. We rebuild the cross-reference table, repair object streams, and re-linearize for fast web view.

A corrupted PDF is one of those frustrations that hits at the worst moment — a downloaded contract won't open, a scanned report renders as a black rectangle, a colleague's exported file shows 'damaged or corrupted' in Acrobat. PDFOnly's PDF repair tool runs your file through qpdf with the cross-reference table rebuilt, object streams regenerated, and the resulting PDF re-linearized for fast web view. If the underlying content is salvageable, you get a working copy back in seconds. Use it as a first step before assuming a PDF is permanently lost.

How to repair pdf step by step

  1. 1

    Upload the damaged PDF

    Drop the file. Even if your PDF reader can't open it, our worker can usually read what's there.

  2. 2

    We try the full rebuild

    First pass: qpdf with --linearize and object-stream regeneration. This handles the most common cases (broken cross-reference table, fragmented object streams).

  3. 3

    Fallback for severely broken files

    If linearization fails (because the file is too damaged for re-streaming), we fall back to a plain qpdf rewrite. This salvages whatever objects are intact and produces a working PDF — sometimes with missing pages if those objects can't be recovered.

  4. 4

    Download the repaired copy

    Output is a fresh PDF that opens in any reader. If pages are missing or content is partially lost, the original was unrecoverable in those spots — at least the rest is now usable.

Why repair pdf on PDFOnly

qpdf, the gold standard

qpdf is the open-source library that pretty much every serious PDF tool uses for low-level repair. Pdftk, Adobe's tools, and many others rely on it. We expose it directly, no proprietary wrapper.

Two-pass repair

If full rebuild fails, we automatically retry with a less aggressive option. Most repair tools give up on the first failure.

Re-linearization included

Repaired PDFs come out optimized for fast web view as a side effect — they load page-by-page in browsers instead of stalling until the whole file downloads.

What people use repair pdf for

A few common scenarios. If your workflow looks like one of these, this tool is a good fit.

Recover a downloaded PDF that won't open

Failed downloads sometimes truncate the file. Repair tries to read everything that's there and rebuild the index. Works for many partial downloads where the body is intact but the trailer is missing.

Fix PDFs from older or buggy software

Some PDF generators (especially older office suites and legacy report tools) produce technically-broken PDFs that some readers tolerate and others don't. Running through repair makes them work everywhere.

Repair PDFs that show as 'damaged' in Acrobat

Adobe is strict about PDF spec compliance. Repair often fixes 'damaged but recoverable' warnings by rebuilding the file structure to spec.

Speed up large PDFs in browsers

Even working PDFs can be slow to load if they're not linearized. Repair re-linearizes them for fast web view (each page loads as needed instead of waiting for the whole file).

What you get

  • Rebuilds the PDF cross-reference table — fixes the most common corruption
  • Regenerates object streams — fixes 'pages not rendering' bugs
  • Re-linearizes for fast web view — your repaired PDF loads page-by-page in browsers
  • Fallback to plain rewrite if linearization fails on truly broken files
  • Lossless when possible — original content preserved
  • Free, no signup, no watermarks

Frequently asked questions

Will repair always recover my PDF?

If the file is salvageable, yes. PDFs damaged beyond their cross-reference table — for example, with truncated object streams or zero-byte content sections — may be only partially recovered. The repair tries the full rebuild first; if that fails, falls back to a plain rewrite that salvages what it can.

What kinds of corruption can you fix?

Common fixes: broken cross-reference table (the index that tells readers where each object is), fragmented object streams, missing trailer, bad linearization, and structural issues that make readers report 'damaged but recoverable'. Can't fix: truly missing data (e.g. a download cut off mid-page-content), encrypted files without the password, or files that were never PDFs to begin with.

Will the repaired PDF look identical to the original?

If the original content is intact and only the structure is broken, yes — the repaired PDF is byte-equivalent in content. If parts of the content were lost (truncated download), those pages may be missing or appear blank in the repaired version.

Can you fix encrypted PDFs that are also damaged?

Repair runs before decryption — so it can fix structural issues even on encrypted PDFs (without needing the password). After repair, you'll still need to unlock with the password to view the content.

Will the repaired file be smaller or larger?

Usually slightly smaller — re-linearization removes duplicate objects and tightens the structure. For badly fragmented PDFs, savings can be significant (10-30%).

What if your repair tool can't fix my PDF?

If both the linearization rebuild and plain rewrite fail, your PDF is in 'truly unrecoverable' territory. Try opening in Adobe Acrobat (it has its own repair routines), or try recovering via a content-extraction tool like pdftotext to at least pull out the text. As a last resort, contact us with the file and we'll see if a custom recovery is possible.

Are there any privacy concerns?

Same as our other tools — files upload over HTTPS, are processed in isolated workers, and are auto-deleted within an hour. We never train AI models on customer documents.

Ready to repair pdf?

Free to use for the basics. Files are auto-deleted within an hour and never used to train AI.

Open Repair PDF