Windows Photos throws “It looks like we don’t support this file format” for a .jpg for one of three reasons. The file is mislabelled. It is actually HEIC or WebP wearing a .jpg extension. The Photos app itself has stumbled. Or the JPEG data is genuinely damaged. Fix the right one.

Check If the File is Mislabelled

Renaming a file’s extension does not change its actual format. A file saved as .jpg may still contain HEIC or WebP data. Windows Photos cannot decode those formats, so it shows the error message.

Read the Real Format from Raw Bytes

Open the file in a hex viewer or a text editor that shows raw bytes. Look at the first few bytes:

  • A real JPEG starts with the bytes FF D8 FF.
  • A HEIC file contains “ftypheic” (or a similar ftyp brand) near the start.
  • A WebP file starts with “RIFF” and contains “WEBP”.

If you see HEIC or WebP markers, the file is not a JPEG. For HEIC files from an iPhone, install the HEIF Image Extensions from the Microsoft Store. For WebP files, use a browser or a dedicated converter. Do not simply rename the extension.

Test If the Problem is the App

If the file really is a JPEG (starts with FF D8 FF) but Windows Photos still refuses it, the issue may be with the Photos app itself. Confirm it by opening the same file in another program.

Quick App Test

  1. Right-click the file and choose Open with.
  2. Select Paint (comes with Windows). If Paint shows the picture, the file is readable and the problem is limited to the Photos app.
  3. Alternatively, open your web browser and drag the file into the browser window. If it displays, the file is fine.

If the file opens in Paint or a browser but not in Windows Photos, update the Photos app or reset it in Windows Settings. The error “Windows Photo Viewer can’t display this picture because the file appears to be damaged, corrupted, or is too large” is a separate message from Windows Photo Viewer, not the Photos app.

Identify a Truly Damaged JPEG

If the file does not open in Paint or a browser either, the JPEG data is likely damaged. The file may have been broken during transfer, storage, or a failed edit. In this case, the error message is misleading. The real issue is file damage.

Signs of Damage

  • The file size is much smaller than expected (e.g., 1 KB for a photo).
  • The file opens as a blank or grey image in a viewer that normally handles JPEGs.
  • The hex view shows the correct JPEG start bytes but the rest of the data is garbled or truncated.

If the file is truly a JPEG and still fails, the most reliable fix is to re-encode the readable pixels into a clean JPEG. Tools that extract whatever image data remains and produce a new, valid JPEG file are the best option.

Fix a Damaged JPEG by Re-encoding

When a JPEG is damaged but parts of the image are still visible (or the file structure is partially intact), re-encoding the readable pixels produces a clean JPEG. This process discards broken metadata and rebuilds a standard JPEG file.

To do this:

  1. Open the damaged file in a program that can read partial data (e.g., an image viewer that attempts recovery).
  2. If any part of the image displays, take a screenshot or use a “save as” option to re-save it as a new JPEG.
  3. If the file is completely unreadable, use a dedicated repair tool that scans for recoverable JPEG segments.

One such tool is jpeg.repair, which recovers damaged JPEG files online for free with no watermark. Upload the file and the service attempts to rebuild a clean JPEG from the recoverable data.

Prevent Future File Format Errors

Most format errors happen because of format confusion. To avoid them:

  • When saving photos from an iPhone, turn off High Efficiency mode (HEIC) in the camera settings, or install the HEIF Image Extensions on Windows.
  • When downloading images from the web, check that the file extension matches the actual format. WebP files are common and need a browser or converter.
  • Always use a proper image converter to change formats. Renaming a file from .heic to .jpg never works.

If you already have a collection of mislabelled files, batch-rename them to the correct extension after verifying the format with a hex viewer.

Summary of Quick Checks

Use this order to diagnose the error:

  1. Check the file’s first bytes: FF D8 FF means JPEG; “ftypheic” means HEIC; “RIFF” + “WEBP” means WebP.
  2. If it is HEIC or WebP, install the correct codec or use a compatible app.
  3. If it is a real JPEG, open it in Paint or a browser. If it works there, the Photos app is the issue.
  4. If it does not open anywhere, the file is damaged. Try re-encoding the readable pixels or use a repair service like jpeg.repair.