Can I fix the error by just renaming the file?

Only if the file is actually a different format, like PNG or WebP, saved with a .jpg extension. Renaming to the correct extension lets other apps open it, but you still need to convert it to a real JPEG before Photoshop will accept it.

Why does the file open in my browser but not in Photoshop?

Browsers are lenient about file extensions and marker errors. They often display the image regardless of the extension or minor corruption. Photoshop, however, strictly checks the internal marker structure and will refuse a file that does not match JPEG specifications.

Will using a repair tool change the image quality?

Re-encoding always involves some quality loss if you use lossy JPEG compression. To minimize loss, save with the highest quality setting available. If the original was already a JPEG, the change is usually negligible.

What if the image does not display in any app at all?

If no app can open the file, the corruption may be too severe for a simple re-encode to fix. In that case, the image data itself may be lost, and recovery may not be possible.

Photoshop "Unknown or Invalid JPEG Marker Type" Error Fixed

Photoshop refuses to open a JPEG and shows "Could not complete your request because an unknown or invalid JPEG marker type is found." The cause is usually one of two things: the file is not actually a JPEG despite its .jpg suffix, or the file has a damaged marker in its internal structure. Here are both causes and the fixes that do not require Photoshop itself.

What the Error Means

The full error text reads: "Could not complete your request because an unknown or invalid JPEG marker type is found." A related error you might see is: "Could not complete your request because it is not the right kind of document." Both mean Photoshop cannot parse the file as a valid JPEG.

JPEG files are built from markers that start with the byte FF. Common ones include FF D8 (start of image), FF DB (quantization table), FF C4 (Huffman table), FF DA (start of scan), and FF D9 (end of image). If Photoshop encounters a byte sequence that does not match any known marker, or if the markers appear in the wrong order, it stops and shows the error.

Two Main Causes

Cause 1: A File That Is Really Another Format

A frequent cause is a PNG, WebP, or HEIC file that has been saved with a .jpg suffix. The file will open in a web browser or a basic image viewer, which often ignore the suffix. Photoshop expects a true JPEG structure. A PNG file, for example, begins with the bytes 89 50 4E 47, while a JPEG begins with FF D8 FF. When Photoshop sees 89 50 4E 47 instead of FF D8 FF, it cannot proceed.

Cause 2: A Damaged Marker

Even if the file is a real JPEG, a single corrupted byte in a marker can cause the error. This can happen from an interrupted download, a faulty memory card, or a bad transfer. The marker might be missing, have an invalid length, or contain unexpected data.

Check the File Format First

Before trying to repair the file, confirm whether it is actually a JPEG. You can do this without any special software:

Open the file in a plain text editor like Notepad on Windows or TextEdit on macOS. You will see a lot of garbled characters, but look at the very beginning.
If the first few characters are ÿØÿ, which corresponds to FF D8 FF in hexadecimal, the file is likely a real JPEG.
If you see ‰PNG, from 89 50 4E 47, the file is actually a PNG with a .jpg suffix.

If the file is not a real JPEG, renaming the suffix back to .png, .webp, or .heic will let you open it in other apps. Then you can convert it to a proper JPEG from there.

Fix a Real JPEG with Damaged Markers

If the file is a genuine JPEG but the markers are damaged, the simplest fix is to open the file in another application and save a new copy. Re-decoding and re-encoding the image writes a fresh set of valid markers. The damaged original markers are replaced with clean ones during the save process.

Using a Basic Image Viewer

Many free image viewers, such as the default Photos app on Windows or Preview on macOS, can open JPEGs that Photoshop cannot. Open the file in the viewer, then use the Save As or Export option to create a new JPEG file. Try opening that new file in Photoshop.

Using a Web Browser

Most web browsers, including Chrome, Firefox, and Edge, can display JPEG images even if they have minor marker errors. Drag the file into a browser window. If the image appears, right-click it and select "Save Image As" to save a new copy. That new copy should open in Photoshop.

Using an Online Repair Tool

If you prefer not to install anything, use a site like jpeg.repair to recover the image. The service re-decodes and re-encodes the file, producing a clean JPEG with valid markers.

What to Do When the File is Actually Not a JPEG

If you discovered that the file is a PNG, WebP, or HEIC saved with a .jpg suffix, you have a few options:

Rename the suffix to the correct one, such as .png. The file will then open in any app that supports that format.
Convert it to JPEG using any image editor or converter. Open the correctly renamed file in a basic image viewer, then save a copy as JPEG.
Use an online converter that accepts the original format and outputs a true JPEG. This will give you a file with proper JPEG markers that Photoshop can open.

Once you have a real JPEG file, Photoshop should open it without the "unknown or invalid JPEG marker type" error.

Preventing the Error in the Future

To avoid this error, pay attention to file suffixes when saving images. Many apps save in their native format, such as PNG for screenshots or WebP for web images, and only change the suffix if you manually rename the file. Always use the Save As or Export function to choose JPEG as the format, rather than just changing the suffix.

If you receive images from others, you can quickly check a file's true format by looking at its first few bytes as described above. This takes only a few seconds and can save you the trouble of a Photoshop error later.