How to recover video from a corrupted SD card (safely)

By the FixMP4 engineering team · October 9, 2026 · 11 min read

An SD card that suddenly says "you need to format the disk before you can use it", shows as empty, or makes your camera display "card error" is alarming, especially when it holds video you cannot reshoot. The way you handle the next hour matters more than which software you use, because the most common way people lose footage permanently is by doing the wrong thing in a panic.

This guide covers what to do and in what order: protect the card, copy what you can, recover lost files, and then repair the videos that come back damaged. We make a video repair tool, and we will be clear about where it fits: it repairs files that will not play, it does not recover files from a card. For that, you need the free tools described below first.

First: what not to do

• Do not format the card, whatever the computer or camera suggests.
• Do not record, take photos, or copy anything onto the card. Every new write can overwrite the data you want back.
• Do not run disk repair tools such as chkdsk with fix options, or First Aid on a Mac, before recovery. They can "fix" the file system by discarding damaged entries, including your videos.
• Do not keep reinserting the card into different devices if it is physically unstable or getting hot.

If possible, flip the lock switch on the side of a full-size SD card to read-only.

Step 1: Work out what kind of problem you have

Step 2: Try a different reader

Cheap card readers and laptop slots fail more often than cards. Try a good USB reader on another computer. If the files suddenly appear, copy everything immediately.

Step 3: Make an image of the card

For important footage, the safest method is to make a complete copy of the card, an image, and recover from that instead of the card. That way the card is read once, and you can retry recovery as many times as you like.

• Linux and Mac: GNU ddrescue is free and designed for failing media; it copies the readable areas first and retries bad areas later.
• Windows: several free imaging tools can create a raw image of a removable drive.

You need free space at least equal to the card's capacity. If the card is reading normally and quickly, you can skip this and recover directly, but imaging is never a mistake.

Step 4: Recover the files

Recovery tools fall into two groups:

• File system recovery reads the remains of the card's file system to find deleted or lost entries, often with original names and folders.
• File carving ignores the file system entirely and scans the raw data for known file signatures, such as the start of an MP4. It works even after a format, but recovered files usually lose their names, and fragmented files may come back incomplete.

PhotoRec is a well-known free and open-source carving tool that runs on Windows, Mac and Linux and supports MP4 and MOV. Its companion TestDisk can sometimes repair a damaged partition table so the whole card becomes readable again. Commercial tools offer friendlier interfaces and previews. Whatever you use, always save recovered files to a different drive, never back to the card.

Expect a mix of results: many files intact, some missing, and some that are recovered but will not play.

Step 5: Repair recovered videos that will not play

Video files recovered from a failing card are often damaged in a specific way: the frames are present, but the file's index, the moov atom, is missing or broken. This happens because:

• The camera was recording when the card failed, so the last file never got its index.
• The card's damage cut off the end of the file, where most cameras write the index.
• A carving tool found the start of the file but not where the index was stored.

These files show 0:00, refuse to open, or give a "moov atom not found" error. They are the case that index rebuilding is built for. (What is the moov atom?)

FixMP4 rebuilds the index inside your browser:

1. Pick an intact video from the same card or the same camera with the same settings as a reference. A clip recovered intact is ideal. See how to choose a reference file.
2. Open the repair tool and add the broken file and the reference.
3. Watch the free preview to confirm your footage is back.
4. Export the full repaired file with a subscription.

Realistic expectations

• Missing index, frames intact: usually a full recovery.
• File cut short by damage: the part that was recovered can be repaired; the rest is not in the file.
• Fragmented carving results: if a carving tool joined pieces of different files, the result may show glitches or switch scenes. Better recovery, for example from the file system rather than carving, can help.
• Holes inside the file: the frames around the hole are recovered, with a short glitch at the damaged part.

Camera-specific tips

• GoPro: try the camera's own repair first by inserting the card and powering on. See GoPro file corrupted.
• DJI drones: power on with the card inserted to let the drone close the last file. See DJI video corrupted.
• Dashcams: cards are overwritten in loops, so remove the card as soon as possible. See dashcam footage corrupted.
• Mirrorless and DSLR cameras: some write MOV or MP4 with H.264 or HEVC, which can be repaired; others use formats such as ProRes RAW or XAVC variants that are not supported.

When to go to a professional

If the card is not detected at all, has physical damage, or holds footage that is irreplaceable and valuable, a professional data recovery lab is worth considering. They can read memory chips directly when the card's controller has failed. Stop all DIY attempts before sending a card in, because every attempt adds wear.

Preventing card failures

• Buy cards from reputable sellers; counterfeit cards often report a fake capacity and corrupt data when they fill up.
• Use cards rated for your camera's sustained write speed (for example V30 or V60 for 4K).
• Format in the camera, not on a computer.
• Replace cards that show any errors, and replace dashcam cards regularly.
• Do not fill cards to the last megabyte.
• Copy footage off promptly and keep two copies of anything important.

Summary

Protect the card, do not format or write to it, image it if the footage matters, recover the files with a tool like PhotoRec onto another drive, and then repair any recovered videos that will not play. FixMP4 handles that last step: preview the repair for free to see whether a recovered file can be brought back. For more background, read why recordings get corrupted and our guide to repairing corrupted video.

• SD cards
• data recovery