How to Repair a Damaged PDF Online: What to Check

1. Protect the original before trying a repair

Make a separate copy of the damaged PDF and leave the original untouched. If the file came from an email, website or cloud drive, check whether you can download it again; a fresh copy may solve an incomplete transfer without any repair step.

Try opening the file in another trusted PDF reader. If only one application reports an error, the issue may be viewer-specific rather than damage to the PDF itself. Also check that the file is not empty and that its extension matches the actual file type.

2. Try the PDFora repair workflow

Open the Repair PDF page, choose the copy of the damaged file and start the repair attempt. Wait for processing to finish, then download the recovered PDF if a result is produced. The tool makes a best-effort attempt to rewrite the file; it does not promise recovery of every damaged document.

Do not upload the only copy of an important record and do not overwrite the source with the downloaded result. Keep both files until you have checked the recovered version.

1. Keep an untouched backup of the source PDF.
2. Select the copied file on the Repair PDF page.
3. Run the repair attempt and wait for the result.
4. Download the recovered copy and open it in a PDF reader.

3. Check what was recovered

A file that opens is not necessarily a complete recovery. Compare the recovered copy with the source or another copy when available. Check the total page count, first and last pages, text, images, tables, page dimensions and reading order. Pay extra attention to pages that were missing or unreadable before the repair.

Bookmarks, form fields, annotations, embedded attachments and interactive elements may not survive a rewrite exactly as they were. If the PDF contains a digital signature, verify it again: changing the underlying file can invalidate a signature even when the visible page looks unchanged.

4. Understand when repair may not work

A repair tool cannot restore bytes that are missing from a truncated download, recreate pages that were never stored, or guarantee recovery from severe corruption. Password protection, unusual PDF features and damaged embedded resources can also prevent a successful result. If the file is important, ask the sender for a fresh copy rather than relying on an incomplete recovery.

If the PDF opens but is simply too large, use compression instead of repair. If the pages are intact but appear sideways, use a rotation tool. If you only need to inspect document properties, start with PDF Information.

5. Handle recovered documents carefully

PDFs can contain personal details, signatures, financial information and confidential records. Upload only documents you are authorised to process, and review the privacy information before using an online service for sensitive material. Keep a local backup until the recovered file has been checked and accepted by its recipient.

For official, legal, financial or academic submissions, confirm the receiving organisation's requirements and retain the original source. A successful download is not proof that every page or embedded feature has been preserved.

Frequently asked questions