What Is a PSB File?

This article describes everything about PSB files, like how to open one and your conversions options to save it to a format that might be easier to open and share.

What Is a PSB File?

A file with the PSB (Photoshop Big) file extension is an Adobe Photoshop Large Document file. The format is almost identical to Photoshop's more common PSD format, except that PSB supports significantly larger files, both in image dimension and overall size.

More specifically, PSB files can be as large as 4 EB (over 4.2 billion GB) with images that have a height and width of up to 300,000 pixels. PSDs, on the other hand, are limited to 2 GB and image dimensions of 30,000 pixels.

Some subtitle files use this same file extension, but they are text files used by the PowerDivX multimedia player as a format for saving subtitles.

How to Open a PSB File

PSB files that are images can be opened with Adobe Photoshop. If you don't own that program, and you're not interested in installing the free Photoshop trial, a completely free way to use the file is with the online image editor Photopea, which remarkable looks and feels a lot like Photoshop. Photopea works on any computer from a web browser, and can load the file from your computer, Google Drive, or Dropbox.

Any text editor can open PSB subtitle files since they're just plain text files, but a program like VLC is what you need to actually run the subtitles along with a video. VLC supports not only PSB subtitles but also SRT, CDG, MPL2, SUB, UTF, VTT, and TXT. Use the Subtitle > Add Subtitle File menu to open one.

How to Convert a PSB File

Photoshop is the best way to convert a PSB file to another format. It supports saving to PSD, JPG, PNG, EPS, GIF, and several other formats. Those options and others, like PDF and SVG, are also supported in Photopea.

Another way to convert a PSB file without using Photoshop is with a free file converter like Aconvert. This website can convert the file to over a dozen other formats. The only downside is that the upload file size is probably limited.

If you'd rather use a desktop tool instead, Filestar, which runs on Windows and macOS, can convert from PSB to dozens of other formats.

Still Can't Open It?

If your file doesn't open with the programs linked above, it's probably a totally different file. This might happen if you've misread the file extension, which is easy to do and will result in an unrelated file format trying to open in a graphics program.

PBS is one example. This file extension is used by PaintShop Pro brush strokes files. You can't open one with Photoshop, even though the file extension is similar to PSB.

SPB is another that could be a Flight Simulator Mission file or a Samsung Kies Phonebook file, but neither are related to a Photoshop format.

If you really have a PST file, then it's probably email data it's storing, not images.