# Repair PDF > Repair a corrupted PDF online, free. Rebuilds broken file structure so damaged PDFs open again. Success depends on how damaged the file is. Fix a PDF that won't open, so you can read and use your file again. Use it free in your browser: https://fynepdf.com/tools/repair-pdf - Recovered pages keep their quality - No watermark on downloads ## Features ### Structural File Rebuild Rebuilds damaged headers, cross-reference tables and streams. ### Repair on Any Device Works in any browser on Mac, Windows, Linux, iPhone and Android. ### Then Save It as PDF/A Convert the recovered file to PDF/A so it stays easy to open for years. ## Three Steps to Rescue Your PDF Repair a PDF in three steps, no software to install, no account needed. 1. **Upload your damaged PDF**: Drag and drop your corrupted, unreadable file up to 600MB on the free plan and 5GB on paid. 2. **Advanced file reconstruction**: FynePDF scans the file structure and rebuilds the header, cross-reference table and page tree. 3. **Download the Result**: If recovery is successful, your repaired PDF is ready to download immediately and auto-deleted after 15 min. ## Salvage Your Unreadable Documents. File corruption happens. When disaster strikes, our advanced repair engine gives you the best possible chance of saving your critical data. - **Interrupted Downloads**: Fix files that broke when your internet dropped mid-download to make them readable again. - **Unexpected System Crashes**: Rescue the important report you were working on when your computer crashed or lost power during the save process. - **Corrupted Storage Drives**: Attempt data recovery on vital PDF files pulled from failing hard drives, ancient USB sticks, or damaged physical storage devices. - **Software Export Errors**: Fix fatal formatting errors and broken file headers caused by faulty third-party PDF creators or buggy export software. - **Broken Email Attachments**: Repair confidential documents that were accidentally corrupted, truncated, or improperly encoded during email transfer. - **Legacy File Rescue**: Restore heavily outdated or improperly coded legacy PDFs from older software that modern document viewers refuse to open. ## How PDF repair works A PDF is a structured file, a header, a set of objects holding your pages, and a cross-reference table that says where each object lives. Corruption usually damages that structure rather than the content, which is why a file can be unopenable while your pages are still intact inside it. FynePDF rebuilds the structure from what survives. - **What gets fixed**: Broken headers, damaged cross-reference tables, malformed object streams and files truncated by an interrupted download. - **What can't be fixed**: Content that isn't in the file at all. If bytes are missing, no repair tool can invent them, those pages are gone. - **Your pages are untouched**: Repair rebuilds structure without re-rendering. Whatever is recovered comes back at original quality. ## After repairing your PDF - [Compress PDF](https://fynepdf.com/tools/compress-pdf): Repaired files can be larger than the original. - [Organize PDF Pages](https://fynepdf.com/tools/organize-pdf-pages): Remove any pages that didn't survive. - [OCR PDF](https://fynepdf.com/tools/ocr-pdf): Recover text from pages that came back as images. ## Frequently asked questions ### What types of PDF corruption can FynePDF fix? FynePDF repairs structural damage, broken file headers, damaged cross-reference tables, malformed object streams, and files truncated by an interrupted download or transfer. These are the most common causes of "the file is damaged and could not be repaired" errors, and in most cases the pages themselves are intact inside the file and simply can't be located. What can't be fixed is missing data: if part of the file was never saved or was lost entirely, that content isn't recoverable by any tool. ### Will repairing a PDF restore all content exactly as it was? Often, but not always. When corruption is structural, recovery is usually complete and every page comes back at original quality, nothing is re-rendered or re-compressed. When data is genuinely missing, FynePDF recovers everything still present and rebuilds a working file around it, which may mean some pages are lost or partially rendered. Always check the repaired file before deleting your original. ### Is the Repair tool free to use online? Yes, FynePDF's Repair PDF tool is free with no sign-up required. Free accounts repair files up to 600MB, with 10 tasks and 600MB of processing a day. Professional at $7/month raises this to 5GB with unlimited daily tasks. ### Is it safe to use Repair on FynePDF? Are my files secure? File transfers use TLS encryption. Cloud-processed files are automatically deleted within 15 minutes after processing completes, unless you choose to save them to your Library. Documents are not used to train AI models. Read the Privacy Policy for storage and processing details. ### Can I use the Repair tool on Mac, Windows, or mobile? Yes. FynePDF's repair tool works directly from your browser, so it works on Windows, Mac, Linux, iOS and Android with no installation. Chrome, Firefox, Safari and Edge are all supported. ### Why won't my PDF open? The most common causes are an interrupted download that left the file incomplete, a crash during saving, a faulty PDF export from third-party software, or corruption picked up in transfer. All of these damage the file's structure while usually leaving the page content intact, which is exactly what Repair PDF rebuilds. If the file opens but asks for a password, that's not corruption, use Unlock PDF instead. ### What does "the file is damaged and could not be repaired" mean? That's Adobe Acrobat's message when it can't parse a PDF's structure, usually a broken cross-reference table or header rather than damaged page content. Acrobat gives up at that point, but the underlying pages are often still present and recoverable. Upload the file to FynePDF's Repair PDF and it will attempt to rebuild the structure around whatever survives. ### What if the repair doesn't work? If FynePDF can't recover the file, the data needed is most likely missing rather than misplaced. Worth trying before you give up: any earlier copy in your email, cloud storage or version history; your application's autosave or temp folder; and re-downloading or re-exporting the original if it came from elsewhere. A file that's 0 KB or only a few bytes contains nothing to recover, whatever tool you use. ### Will repairing change my document's content or quality? No. Repair rebuilds the file's structure without touching the pages themselves, so text stays selectable and images keep their original resolution. Repaired files are occasionally slightly larger than the original because the structure is rewritten cleanly, Compress PDF will bring the size back down. --- Open this page in a browser: https://fynepdf.com/tools/repair-pdf More: [All tools](https://fynepdf.com/tools) · [AI agents](https://fynepdf.com/ai/agents) · [llms.txt](https://fynepdf.com/llms.txt) · [Sitemap](https://fynepdf.com/sitemap.xml)