Repair PDF Online
Analyze a damaged or incompatible PDF and attempt the least destructive browser recovery that works.
Your document is processed locally and is not uploaded to a repair server.
Select a PDF File
Choose a PDF from your device or drag it here. The browser will test its structure and readable pages.
Recovery method
Visual salvage quality
Repairing PDF…
Analyzing PDF…
Repair complete
How PDF Repair Works
A PDF can fail for many reasons, so Repair PDF does not use a single “magic fix.” The browser first checks the file signature, then attempts to read it with PDF.js and pdf-lib. These independent checks help distinguish a healthy document, a file that can be structurally rewritten, a file whose pages are visually renderable even when direct rewriting is unreliable, and a file that is too damaged for browser recovery.
The automatic workflow prefers the least destructive recovery that works. Structural Rewrite keeps PDF page objects rather than turning them into images. Visual Salvage is a fallback that renders readable pages and rebuilds a new PDF from those page appearances. The result always reports the method actually used.
Structural Repair vs Visual Recovery
Structural Rewrite asks pdf-lib to parse the source and serialize a new PDF. This can normalize some malformed structures and compatibility issues, but it cannot repair arbitrary missing objects. Visual Salvage uses PDF.js rendering instead. If a page can still be drawn in the browser, the tool can recreate that page as an image inside a new PDF. This approach is useful for visible recovery but can flatten selectable text, forms, links, annotations, bookmarks and signatures.
Can Every PDF Be Repaired?
No. If both parsers fail before any usable page can be identified, there is no honest browser-side result to generate. In that state the tool reports that no usable pages were recovered instead of creating an empty file. Severely truncated documents, overwritten objects, unsupported encryption, and damaged streams may be unrecoverable.
Recovering Individual Pages
Visual Salvage tests pages sequentially. A rendering failure on one page does not automatically discard pages that remain readable. The recovery report lists the number of detected, recovered, and failed pages. Failed pages are never silently described as recovered.
Password Protection vs Corruption
An encrypted PDF is not necessarily damaged. This tool does not crack passwords or treat encryption as corruption. If the browser identifies a password-protected file, unlock it with an authorized password first and then retry the repair workflow.
Digital Signatures and Repair
PDF signatures protect a particular byte state. Rewriting or rebuilding a document changes those bytes and normally invalidates an existing cryptographic signature. Keep the original signed file when signature verification matters.
Does Repair Change Quality?
Structural Rewrite aims to keep original page content. Visual Salvage is intentionally lossy because it recreates pages from rendered images. High Quality Recovery uses more pixels and a higher JPEG quality than Smaller Recovered File, but it also consumes more memory and generates larger output.
Browser Privacy
The selected PDF is read from your local file input and processed in browser memory. The repair workflow has no document-upload endpoint. The production page may request the pinned parser libraries themselves, but the source filename and PDF bytes are not sent as payloads to a repair service.
Troubleshooting
If a file is healthy but a specific application rejects it, try Structural Rewrite. If rewriting fails but you can still view pages, try Visual Salvage. For encrypted documents, unlock them first. If no pages can be parsed or rendered, use a backup copy or a specialized desktop recovery application because browser salvage cannot invent missing document data.
Common Causes of PDF Damage
PDF problems can appear after an interrupted download, incomplete file transfer, application crash, incorrect incremental save, damaged storage media, or a program that writes malformed object references. Some files are technically valid but expose compatibility bugs in a particular viewer. That is why the analysis checks more than the filename extension and why a healthy classification does not claim the file is defective.
Structural problems also differ from content problems. If a page image stream itself is destroyed, rewriting the surrounding PDF structure cannot recreate the missing pixels. Conversely, if visible page streams remain readable but cross-reference or serialization data is troublesome, a tolerant parser or visual salvage workflow may still recover useful material.
How the Recovery Report Helps
The report separates pages detected from pages recovered. For structural rewrite, those numbers should match because the complete document is serialized and then validated. For visual salvage, each page is rendered separately; if one page fails while others succeed, the tool reports a partial recovery and identifies the failed page numbers. This avoids the dangerous situation where a shortened document is presented as if nothing were missing.
Why Visual Salvage Uses Images
When a parser can render a page but cannot safely copy its original objects, rebuilding from a rendered image creates a simple new page structure. This can bypass some object-level problems because the new document contains fresh page objects and JPEG image streams. The cost is loss of semantics: text selection, bookmarks, forms, links, annotations and digital signatures are not reconstructed by this visual path.
Repairing PDFs on Mobile Devices
Mobile browsers can perform the same client-side workflow, but high-quality visual salvage may require substantial RAM. The tool bounds canvas dimensions and processes one page at a time. A long image-heavy document can still exceed a phone's practical memory, so desktop processing is preferable for very large recovery jobs. The tool does not impose a misleading tiny file-size limit because page complexity matters more than the file's MB number alone.
When to Use a Desktop Recovery Application
If neither PDF.js nor pdf-lib can obtain usable content, browser recovery has reached its limit. Specialized desktop software may support deeper xref reconstruction, object-stream recovery, or forensic analysis. This web tool does not pretend to include those engines when it does not. For irreplaceable documents, work on a copy and preserve the damaged original before attempting further repair.
Repair PDF FAQ
Can every damaged PDF be repaired?
No. Recovery depends on what valid structure or renderable page data remains.
What happens if some pages cannot be recovered?
The tool reports partial recovery and the exact failed page numbers. It does not call the result a complete repair.
Can you repair password-protected PDFs?
Password protection is handled separately from damage. Unlock the file first; passwords are not cracked.
Does repair affect digital signatures?
Yes. Rewriting or rebuilding can invalidate existing cryptographic signatures.
Does Visual Salvage preserve searchable text?
No guarantee. It rebuilds the visible page as an image, so searchable text and interactive elements can be flattened.
Are files uploaded?
No document upload is used by the repair workflow.
Why does a healthy PDF show a Rewrite option?
A readable PDF can still have compatibility problems in another application. Rewriting may normalize some serialization issues.
Will repaired pages keep their size and orientation?
Visual Salvage uses each rendered page's visible geometry so portrait, landscape, rotated and mixed-size pages are preserved as closely as practical.
When to Use Structural Rewrite or Visual Recovery
Structural Rewrite is preferable when the PDF remains parseable because it can preserve native page objects instead of converting every page to an image. Visual Recovery is a fallback for files whose pages can still be rendered but whose internal structure cannot be rewritten reliably. The visual method rebuilds only what the browser can actually see, which is useful for salvage but can remove searchability and document-level features.
For important records, keep the damaged original until you have checked the repaired download. Compare page count, orientation, page size, diagrams, photographs, and any information near the damaged area. A repaired PDF is a newly generated file, and cryptographic signatures or interactive content should not be assumed to survive reconstruction.