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Repair PDF FREE | Fix Corrupted, Damaged & Unreadable PDF Files

Automatically repair corrupted, damaged, or unreadable PDF files directly in your browser. Choose Quick Fix to rebuild the structure and recover all text and vectors, or Deep Recovery to rescue every page from a severely damaged file by rendering it fresh. Zero uploads, zero risk. 100% free, no sign-up required. Enjoy One Doc!

100% Local Privacy
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Two Repair Modes
Unlimited Usage

Select Damaged PDF to Repair

Corrupted | Damaged | Unreadable | Truncated | Any broken PDF

How it works

01

Open Damaged File

Upload your broken PDF. The file is immediately analysed in your browser we detect structure errors, missing markers, and cross-reference issues before you choose a repair mode.

02

Choose Repair Mode

Quick Fix rebuilds the PDF structure using pdf-lib, preserving text and vector quality. Deep Recovery renders every page to an image using PDF.js and builds a fresh PDF from scratch.

03

Download Repaired PDF

Your repaired PDF downloads instantly with a live repair log showing exactly what was fixed. If Quick Fix fails, switch to Deep Recovery with one click to attempt a deeper recovery.

Frequently Asked Questions

PDF files can become corrupted for many reasons. The most common causes include interrupted downloads where the file transfer was cut short before completion, application crashes or power failures during a save operation, storage media errors such as bad sectors on hard drives or corrupted USB devices, and email or cloud transfer issues where binary attachments are stripped or modified in transit. Virus or malware activity can corrupt the binary data inside a PDF. Software bugs in PDF creation tools can also produce structurally invalid files that open in some viewers but not others. Even moving a file between different operating systems can occasionally introduce corruption if the transfer is not handled correctly at the byte level.
Quick Fix uses pdf-lib to reload the damaged PDF and reconstruct its internal structure rebuilding the cross-reference table, fixing incorrect stream lengths, correcting malformed object references, and cleaning metadata. When successful it preserves the original text, fonts, vector graphics, and layout exactly. Deep Recovery takes a completely different approach: PDF.js renders each page to a canvas image, and those images are assembled into a brand new PDF. Deep Recovery can rescue pages from files that are too broken for any structural repair, but the output will be image-based text will not be selectable. Try Quick Fix first for best quality, and use Deep Recovery as the fallback for severely damaged files.
If Quick Fix succeeds, the repaired PDF will look and behave identically to the original. All text will be selectable and searchable, fonts will render correctly, vector graphics will remain sharp at any zoom level, and the page layout will be perfectly preserved. With Deep Recovery, the visual appearance of every page is preserved because content is captured as a rendered image, but text will no longer be selectable or searchable. The file size with Deep Recovery is also typically larger than the original. Quick Fix produces a functionally identical document in most cases, while Deep Recovery is best used when the file is too corrupted for structural recovery and you simply need a readable version of the content.
Completely safe. The OneDoc Repair PDF tool processes your file entirely inside your web browser using pdf-lib and PDF.js two open-source JavaScript libraries that run locally on your device. Your PDF is never transmitted to any server, never stored anywhere outside your own computer, and is not accessible to anyone other than you at any point. This makes it safe to use with sensitive documents including legal contracts, medical records, financial statements, personnel files, and confidential business documents. The tool also works fully offline after the initial page load, once the libraries have loaded, no ongoing internet connection is required for the repair process itself.
If both Quick Fix and Deep Recovery cannot process your PDF, the file may be too severely damaged for browser-based repair. We recommend the following steps: first, check whether you have a backup copy in a cloud service such as Google Drive or Dropbox these services retain previous versions and revision history. Second, contact whoever sent you the file and request a fresh copy directly from the source. Third, if the file was stored on a failing physical drive, a professional data recovery service can sometimes recover partially overwritten data at the byte level. To prevent this in the future, always keep backups of important PDFs in at least two locations our PDF Compressor can make files smaller and easier to store and back up.

About One Doc Studio

One Doc is a professional-grade web studio dedicated to providing Forever Free document and image utilities. We believe that essential tools should never be locked behind subscriptions or hidden paywalls.

Repair PDF Online Free Tool to Fix Corrupted, Damaged and Unreadable PDF Files

The Repair PDF tool on OneDocPDF is designed to help you recover and fix corrupted, damaged, or unreadable PDF files directly inside your browser without uploading your file to any server, without installing any software, and without paying a subscription fee. PDF corruption is a surprisingly common problem: a file that opened perfectly yesterday suddenly refuses to load, shows a damaged cross-reference table error, displays blank pages, or crashes your PDF viewer entirely. This tool provides two complementary repair strategies to handle the full range of corruption scenarios, from minor structural errors to severely damaged binary files that standard tools cannot open at all.

The first repair mode, Quick Fix, works by reloading the damaged PDF through pdf-lib and reconstructing the internal document structure from whatever valid data can be parsed. PDF files are built around a cross-reference table that maps the byte positions of every object pages, fonts, images, and streams and a missing or damaged cross-reference table is one of the most frequent causes of PDF errors. Quick Fix rebuilds this table, corrects incorrect stream lengths, repairs malformed object references, strips invalid metadata entries, and serialises a fresh new copy of the document. When successful, the output preserves all original text, fonts, vector graphics, embedded images, and page layout in full.

The second mode, Deep Recovery, takes a fundamentally different approach for files that are too severely damaged for structural repair. It uses PDF.js the same rendering engine behind Firefox's built-in PDF viewer to render each page to a high-resolution canvas at your chosen quality level. Those rendered page images are then assembled into a brand new PDF using pdf-lib. This approach can recover content from files where the object structure is almost completely destroyed, because PDF.js can often extract and render partial content from heavily corrupted binary data. The available quality settings Standard, High (recommended), and Maximum let you balance output file size against visual sharpness.

After successfully repairing your PDF, you may want to further prepare it for use. If the repaired file contains blank pages resulting from corruption in the original document, our Remove Blank Pages tool will automatically scan and delete every empty page. If the repaired file particularly one produced by Deep Recovery is large, our PDF Compressor uses a smart hybrid engine to reduce file size while preserving visual quality, making it practical for email attachments and document portals.

For documents with pages in incorrect orientations due to corrupted rotation metadata, our Rotate PDF tool lets you permanently correct orientation. When the repaired document needs to be combined with other related files, our Merge PDF tool joins multiple PDFs into one organised document. For professional presentation, our Add Header and Footer tool stamps page numbers, dates, and custom text on every page. If your repaired document contains form fields that need locking, our Flatten PDF tool permanently embeds all interactive elements into the page content.

Understanding what makes a PDF repairable helps set realistic expectations. A PDF is a binary file containing numbered objects stored at specific byte offsets, with a cross-reference table mapping each object's number to its byte position. If this table is corrupted but the objects themselves are intact, Quick Fix can reconstruct a valid table and recover the entire document. If individual streams are truncated or contain invalid compressed data, Quick Fix re-reads them with error-tolerant parsers. If the file is truncated ending before the final cross-reference section Deep Recovery can still extract whatever pages PDF.js can render from the partial data. The live repair log displayed during processing shows exactly which pages were recovered, which objects were skipped, and the final output file size, giving you full transparency into the severity of the original damage and the completeness of the recovery.