Getting a damaged PDF to open again, and what cannot come back
A PDF that opened yesterday shows an error today, or a viewer opens it with pages missing. Usually the pages are still inside the file and what broke is the map that tells a viewer where to find them. This tool rebuilds that map on your device, keeps every page it can read, and tells you what it found and what it had to leave out.
Updated
Which tool you need
The file stopped downloading, or arrived through a flaky connection
Download it again first if you can: a complete copy beats any repair. If the original is gone, repair what you have and every page that arrived whole is kept.
A viewer says the file is damaged, or opens it with pages missing
This tool, as it is. Check the pages it shows afterwards: they are the repaired copy, which is the honest picture of what survived.
A password prompt comes up instead of the pages
A password prompt is not damage. If you know the password, remove it with Unlock PDF, then repair the unlocked copy if it still misbehaves.
The PDF opens fine, but its words are what you need
PDF to Text copies the words out in reading order, which can be quicker than mending a file you only want to quote from.
Structure can be rebuilt, content cannot
A PDF is a set of numbered parts and an index saying where each part starts. An email program that adds bytes, a program that crashes mid-save or a download cut short tends to break the index, or the list of pages, while leaving most parts intact. Those can be found again by reading the file from start to end, which is what the rebuild does.
What a rebuild cannot do is invent bytes that are no longer there. If the instructions that draw a page were cut off, the page shows whatever came before the cut, or nothing. A font or a picture that was itself damaged stays damaged, and a page whose parts are missing entirely does not come back.
Reading the report
After a repair the tool says how many pages it recovered and what it had to do: rebuild the index, remove stray bytes at the start, recreate the list of pages, or leave out parts it could not read. A file with no damage at all is said to be clean and is simply saved again, which points at the viewer, or at a fault in the page contents that a structural rebuild does not reach.
Like every PDF this site writes, the repaired copy has its scripts, automatic actions and attached files removed. If the original held files attached inside it, save those from another copy before you rely on the repaired one.
What to know before you start
- Missing page content is not recreated, only the structure around it.
- Encrypted PDFs are not repaired; they go to Unlock PDF first.
- Fonts and pictures that were damaged stay as they are, or blank.
- Files attached inside the PDF do not survive the repair.