How to Fix a Damaged or Corrupted PDF (Free, Often Recoverable)
PDF won't open? Pages missing or showing blank? Often recoverable in 30 seconds with a repair tool. Free, no install.
You double-click a PDF and your reader says "file is damaged", "cannot be opened", or shows a blank page. Annoying — but often fixable. Here's how to think about it.
First check: is the file actually broken?
Try these before you assume corruption:
- Open it in a different reader. Mac Preview, Adobe Reader (free), browser PDF viewer, Chrome — they all handle slightly different PDF quirks. A file Preview rejects might open fine in Chrome.
- Re-download. If you got it via email or a cloud link, the download may have been incomplete. Try again.
- Check the file size. A 0-byte or KB-sized PDF where you expected MBs is truncated — no repair tool can recover content that isn't there.
- Look at the file header. Open the PDF in any text editor. The
first 5 bytes should be
%PDF-. If they're not, the file isn't a PDF at all — it's something with the wrong extension.
If none of those works, the file is genuinely broken and a repair tool is the next step.
What "repair" actually does
PDFs have an internal index (called the xref table) that tells the reader where each page, image and font lives in the file. When the index is corrupted (interrupted save, partial download), the reader gives up.
A repair tool:
- Ignores the broken index.
- Scans the raw bytes of the file for valid PDF objects (page content streams, fonts, images).
- Rebuilds the index from scratch by finding every valid object and noting its location.
- Writes a new PDF with the recovered objects and a fresh index.
What that means in practice:
- Files broken in the xref but with intact content: recovered fully. This is the most common type of "damage", and it's nearly always fixable.
- Files truncated mid-content: partial recovery — the pages up until the truncation point come back, anything after is gone.
- Files broken in the middle: usually all pages before the break recover; pages after are unreliable.
How to repair — step by step
Open the repair tool
Go to pdfty.com/tools/repair.
Upload the broken file
Drag it in. Free up to 20 MB. Even files your reader can't open will upload — we work directly on the bytes.
Hit Repair
We scan the file, find all recoverable PDF objects, rebuild the index. 5-20 seconds.
Preview the result
The first page of the recovered PDF shows so you can confirm content is there. If it's the right document, proceed; if all pages are blank, the file may be unrecoverable.
Download
The repaired PDF should open in any reader.
What we can and can't recover
| Damage type | Usually recoverable? | Notes |
|---|---|---|
| Corrupted xref / index | ✓ Yes | Most common type. Near-100% recovery. |
| Interrupted save | ✓ Often | Recover up to the last complete write |
| Truncated download | ⚠ Partial | Only what was downloaded comes back |
| Damaged in the middle | ⚠ Partial | Pages before the break recover; after is unreliable |
| Wrong file type (not actually PDF) | ❌ No | Can't recover what was never a PDF |
| Encrypted file with lost password | ❌ No | That's an encryption problem, not damage — see [Unlock](/en/tools/unlock) |
| Empty file (0 bytes) | ❌ No | Nothing to recover from |
Frequently asked questions
Will all the content be recovered?
For the most common type of damage (corrupted index), yes — every page, image and font comes back. For truncated or middle-damaged files, only the intact portion is recoverable. We always show a preview before download so you can decide if the recovery is worth keeping.
Will hyperlinks and bookmarks survive?
Hyperlinks: usually yes (they're embedded in page content). Bookmarks: sometimes — they live in a separate part of the file that may also be damaged. If bookmarks are missing in the recovered file, the content is still there, just without the bookmark sidebar.
What about form fields?
Form data (text you typed into fields) is often lost during recovery because form fields are usually in the damaged metadata section. If the form data matters, recover the file, then re-fill the form before sending.
Does it work for damaged scans?
Yes — but only the container (the PDF) is repaired. If the actual scanned images inside are corrupted (rare), they'd come out blurry or broken. Usually scanned PDFs damage in the container, not the images.
Will the file size change?
Often smaller after repair, because the rebuilt index is cleaner than the damaged one and unused objects get dropped.
Can I repair an encrypted file?
The file needs to be unlocked first — repair works on the file content, not the encryption layer. If you have the password, use Unlock first, then repair.
Is there a file size limit?
Free plan: 20 MB. Pro: unlimited.
Will the PDF open in older readers after repair?
Yes — the rebuilt index uses standard PDF format that every reader supports.
The pdfty team builds privacy-first online PDF tools — compress, convert, OCR, sign and protect. Files are deleted within 1 hour. About us →
