About PSD
PSD has been Photoshop's native format since the first version in 1990. It stores everything needed to keep working on an image: layers, masks, adjustment layers, text, paths, effects and guides. That makes it an excellent working format and a poor delivery format, because only Photoshop, and to varying degrees other editors, understands all of it.
The composite image
With “Maximize Compatibility” turned on, Photoshop also saves a flattened copy of the finished image inside the PSD. That composite is what other software, and this site, uses to show the file accurately, including effects and blend modes. Without it, a converter has to rebuild the image from layers, and complex documents will not come out exactly right.
Large documents
PSD is limited to 30,000 pixels on a side and 2 GB. Larger documents use PSB, the large document format, which is not supported here. Very big PSDs are also heavy to open in a browser; on a phone, expect them to be slow or to be scaled down.
PSD at a glance
| First released | 1990 |
|---|---|
| Compression | Lossless |
| Transparency | Yes |
| Animation or pages | Layers |
| Best for | Working files in Photoshop |
| Support | Adobe and many editors; not browsers |
Questions people ask
Can I edit a PSD here?
No. You can convert it to an image or extract its layers, then edit those.
What is Maximize Compatibility?
A Photoshop save option that stores a flattened copy of the image, so other apps can show it accurately.
Are PSB files supported?
No, only PSD.