Repair a damaged PDF — online & free
Upload a corrupted, broken or unreadable PDF and we'll try to recover it in seconds. Three independent recovery engines run in sequence to give you the best chance of getting a working file back.
PdfDocShift › Repair PDF
✅ Repaired file ready to download!
How PDF repair works — 3 engines, one click
PdfDocShift's Repair PDF tool runs your file through a layered recovery pipeline. We start with the lightest fix — reloading the file with a tolerant parser — and only escalate to heavier rebuilds if that fails. Whichever stage produces a valid PDF first is what you download.
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No sign-up required. Files are encrypted in transit and auto-deleted after 2 hours.
Why Do PDFs Get Damaged in the First Place?
Most "damaged PDF" errors are not caused by content corruption — they are caused by the file's structural metadata being missing or out of date. Every PDF ends with a small index called the cross-reference (xref) table that tells readers where each object lives in the file. If a download is interrupted, a write is cut short, or an editor crashes mid-save, this index can be truncated, leaving the body of the document intact but unreachable. Other common causes include email systems that re-encode binary attachments, USB drives unplugged during transfer, syncing tools that abort halfway, and PDFs created by buggy export plug-ins that produce technically-invalid output. The good news: in nearly all of these cases the actual page content is still present in the file — only the lookup table needs to be rebuilt.
What Recovery Strategies Does PdfDocShift Use?
PdfDocShift's Repair PDF tool runs a three-stage pipeline so you get the best possible result without having to choose a strategy yourself. Stage 1 uses the JavaScript library pdf-lib in tolerant mode. It reads the file with relaxed validation, ignores invalid objects, and re-serialises the document — enough to fix many minor xref-drift problems. Stage 2 calls Ghostscript with -dPDFSTOPONERROR=false. Ghostscript re-builds the cross-reference table and re-encodes every page stream from scratch, which recovers truncated downloads and files where the trailer is completely missing. Stage 3 is a fallback to qpdf, which is the most permissive parser of the three and is excellent at handling malformed object streams and broken length markers. The first stage that produces a valid, non-empty PDF is what you download.
What Repair PDF Cannot Do
It is important to set expectations. Repair PDF is a structural recovery tool — it can rebuild headers, indexes and page references, but it cannot invent content that was never written to disk. If your PDF was truncated below ~1 KB, was actually a non-PDF file renamed with a .pdf extension, or had its core page streams completely overwritten by zero-bytes, no software can recover it. In those cases, your best option is to re-download the original from its source, restore an earlier version from a cloud backup such as Google Drive or Dropbox, or check your operating system's local versioning history (Time Machine on macOS, File History on Windows). If repair succeeds but specific pages render as blank, the page content stream was lost — the file is still openable but those pages cannot be reconstructed.
How Repair PDF Compares to Acrobat's Built-In Recovery
Adobe Acrobat Pro silently runs a similar repair routine when you open a damaged PDF — but it is paid software, requires installation, and won't help if the file refuses to open at all. PdfDocShift's online tool runs three independent open-source engines (pdf-lib, Ghostscript, qpdf) over the same file, which together cover a wider range of corruption scenarios than any single engine alone. There is nothing to install and nothing to pay for; just upload, wait a few seconds and download. Your file is processed in an isolated container, transferred over 256-bit SSL, and permanently deleted from our servers after 2 hours.
Repair PDF questions
Everything you need to know about repairing damaged or corrupt PDF files online.
Repair PDF can recover from a wide range of structural problems: broken or missing cross-reference (xref) tables, corrupted trailers, mis-counted stream lengths, partially-truncated downloads, files saved with the wrong encoding, and PDFs that open with a "damaged file" or "unable to load" error in your reader. It cannot recover content that was never written to disk in the first place.
PdfDocShift runs a 3-stage recovery pipeline. Stage 1 uses pdf-lib in tolerant mode to reload and re-save the file, fixing minor metadata issues. Stage 2 sends the PDF through Ghostscript with PDFSTOPONERROR=false, which rebuilds the cross-reference table and re-encodes the page tree. Stage 3 uses qpdf as a last-resort fallback for malformed object streams. Whichever stage produces a valid PDF first is returned.
In most cases, no. The repair process tries to preserve every page, image and text stream that is still readable. Pages whose content streams are completely missing or unrecoverable may be dropped or render as blank. Form fields, signatures and interactive features may be flattened to static content, depending on which recovery stage succeeds.
Yes. Files are uploaded over 256-bit SSL and stored in encrypted cloud storage tied to your anonymous session. They are processed in an isolated worker container, permanently deleted after 2 hours, and never read, indexed or shared.
The maximum upload size is 200 MB per file. This covers the vast majority of everyday PDFs. If your damaged file is larger and exceeds this limit, contact us and we'll see what we can do.
Some PDFs are too damaged to recover automatically — for example, files truncated below 1 KB or whose page streams are entirely missing. If all three recovery stages fail, you'll see a clear error message. In that case, try re-downloading the original from its source or restoring an earlier version from your cloud backup (Google Drive, Dropbox, OneDrive) or local versioning (Time Machine, File History).
Yes. Like every tool on PdfDocShift, Repair PDF is completely free — no account, subscription or credit card required. There are no daily usage limits beyond the 200 MB per-file ceiling.