Repair Corrupted PDF Files

Key Features

• Byte-level parsing — reads raw PDF object structure rather than relying on a high-level parser that gives up on errors
• xref table reconstruction — rebuilds the PDF cross-reference index from object headers when the original xref is corrupt
• Stream decompression fallback — attempts both FlateDecode (zlib) and raw stream reading if the primary codec fails
• Multi-strategy recovery — runs three separate repair passes and uses the best-quality result
• Recovery report — shows which pages and objects were successfully recovered before you download
• Metadata preservation — retains original title, author, creation date where recoverable
• Handles truncated PDFs — partially downloaded or cut-off files where the trailer is missing
• Runs in browser — corrupt file never uploaded to a server

About PDF Repair

PDF Repair attempts to recover and re-render corrupted or partially broken PDF files that other tools refuse to open. The repair engine parses the raw PDF byte stream, identifies structural errors (broken xref tables, malformed object headers, truncated streams, invalid trailer dictionaries), rebuilds a clean object graph, and re-serializes the document using pdf-lib. Many corrupted PDFs are recoverable because their content objects (text, images, fonts) are intact but the navigation index is damaged — common after incomplete downloads, mid-transfer corruption, or failed save operations.

Most PDF tools simply reject corrupt files with a generic "cannot open" error. This repair tool reads the file at the byte level, attempts multiple recovery strategies (xref table rebuild from cross-referencing object streams, object hunting from known PDF header markers, stream decompression fallback), and reports which pages were successfully recovered versus which had unrecoverable content. You see a recovery report before downloading, so you know whether the repaired file is complete or partial.

Who Uses This Tool

• Recovering partially downloaded PDFs from slow or unstable connections
• Restoring corrupted email attachments that arrived incomplete
• Fixing PDFs corrupted by a failed cloud sync (Dropbox, Google Drive mid-sync saves)
• Recovering files from damaged USB drives or storage with bad sectors
• Salvaging old PDFs created by legacy software with non-standard formatting
• IT administrators recovering production PDFs from corrupted backup archives

How to Use Repair Corrupted PDF Files

1. Step 1: Drop the corrupted PDF into the drop zone. The tool immediately begins parsing the byte stream.
2. Step 2: Wait for the repair analysis — typically 3-10 seconds for files under 50MB. The tool shows a progress bar for each recovery pass.
3. Step 3: Review the recovery report: pages successfully rebuilt are shown green; unrecoverable pages (usually those with physically overwritten bytes) are shown red.
4. Step 4: If the report shows acceptable recovery, click Download Repaired PDF to get the rebuilt file.
5. Step 5: If pages are missing, try opening the original file in a browser tab (Chromium's PDF renderer has independent recovery logic) and use Print to PDF as an alternative.

Frequently Asked Questions