How to reduce PSD file size, and what each method costs

Updated October 8, 2026

To reduce the size of a PSD file without losing any of your work, remove the flattened copy that Adobe Photoshop saves when Maximize Compatibility is on, and store the layers with zip compression. Neither changes a layer or a pixel. On 34 public Photoshop files we tested, those two changes took the total from 878 MB to 472 MB, 46% smaller. Most other advice saves space by throwing part of your work away, which can be fine for a delivery copy but is worth knowing before you do it.

This guide goes through every common method, starting with the ones that lose nothing, with savings measured by us and by others. If you'd like to know where the space goes first, read why PSD files get so big.

Methods that keep every layer and pixel

If you want to reduce Photoshop file size without losing quality, these are the methods to use. Every layer, mask, smart object and pixel stays as it was. The first two do almost all of the work.

Remove the flattened copy

With Maximize Compatibility on, every save stores a full-size flattened copy of your picture next to the layers, for older software and apps that can't read layers. Photoshop itself doesn't need it: when it opens a layered file, it builds the picture from the layers. On our 34 public test files, flattened copies made up 25% of the total (219 MB of 878 MB). Tim Grey found that a file with a Background layer and some adjustment layers is about twice as large with the option on.

There are two ways to remove it. In Photoshop, set Preferences > File Handling > Maximize PSD and PSB File Compatibility to Never or Ask, then open each file and save it again with File > Save As. Or drop the file on Layersqueeze, which writes a copy holding the same blank image Photoshop writes when the option is off.

The cost is in other apps. Adobe's Lightroom Classic help says a layered PSD has to be saved with Maximize Compatibility on before Lightroom Classic can import it, and a Community Expert in an Adobe Community thread gets an error placing a PSD without the copy in Illustrator or InDesign. Keep the copy in files you use there (Layersqueeze lets you switch that step off). If you need it back later, open the file in Photoshop and save it with Maximize Compatibility on. The Maximize Compatibility guide goes into when you need it.

Store the layers with zip compression

Photoshop compresses 8-bit layers with run-length encoding (PackBits), a simple method that only shrinks runs of identical bytes. It works on flat color and does little for painting, photos or grain. For 16 and 32-bit layers Photoshop uses zip, which is much stronger, but it has no setting to use zip for 8-bit layers. The file format allows it, and Photoshop 2026 opens such files.

Layersqueeze stores 8-bit layers with zip, and every pixel stays identical. On its own this saved 21% (188 MB) across our 34 public files, and 8-bit paintings gain the most. 16-bit files gain little from this step, since Photoshop already zips their layers.

Adobe Photoshop 2026 and GIMP 3 opened all 42 of our test files, run through all three Layersqueeze steps, with the same layers and identical pixels. Krita 5.3 showed the same for every file it could check (it can't open some originals, such as 32-bit files). Apps we haven't tested may not read zipped 8-bit layers, so keep the original if the file is going to someone who uses another app.

Clear pasted-document history

Each time you paste or place one document into another, Photoshop adds that document's ID to a list in the file's metadata (photoshop:DocumentAncestors) and never removes old entries. In templates reused for years the list can get huge: Prepression reports files with 100,000 lines of it and a 65 MB file that dropped to 110 KB once it was removed. In most files it's small. Across our 34 public files it came to 48 KB in total, and the biggest list we found was 33 KB (444 documents). Layersqueeze clears the list in the document's own metadata. Embedded smart objects keep their own copies of the list, and Layersqueeze leaves those as they are; the Prepression article links free scripts that clean both.

Save as a layered TIFF with ZIP

Photoshop's TIFF options include a Layer Compression setting, and choosing ZIP there zips the layers. In the Creative Market test described below, this made a 249.2 MB file 120.8 MB. The tester noted it saves very slowly. The file is no longer a PSD, and Adobe's file format help warns that other apps see only the flattened image in a layered TIFF.

Zip the file for sending

Putting a PSD in a .zip or .7z archive loses nothing and works with tools built into Windows and macOS. How much it saves depends on the file, and the person receiving it has to unzip it before opening it. How to send a large PSD file covers this and the upload limits you'll run into.

Methods that cost something

Each of these makes the file smaller by giving up part of your work. Do them in a copy and keep the layered original.

Does merging layers reduce file size?

Yes, often by a lot, because the merged layer stores each pixel once where the separate layers stored it several times. In an Adobe Community thread, a design team's 400 MB template came to 130 to 150 MB with its layers merged. Adobe's own help page on file size suggests flattening or reducing layers. The cost is that you can't edit the merged layers separately again.

Convert 16-bit to 8-bit

Image > Mode > 8 Bits/Channel halves the pixel data. You lose the extra tonal range that keeps gradients smooth under heavy edits. The file on disk may shrink by less than half, because Photoshop zips 16-bit layers but uses weaker run-length encoding for 8-bit ones.

Link smart objects instead of embedding them

An embedded smart object carries a full copy of the file you placed. File > Place Linked, or Layer > Smart Objects > Convert to Linked, stores a path to the file instead. Adobe's smart objects overview says this can make documents smaller, but the layer still stores a rendered copy for display, which can be larger than the source, so the saving varies. The PSD then depends on the linked files: move or delete them and those layers can't be edited.

Rasterize smart objects

Rasterizing drops the embedded file and keeps only the pixels you see. You can no longer edit its contents, or scale it up without losing detail.

Crop, delete or downsize

• Crop off pixels outside the canvas. Layers that reach past the edge store those hidden pixels too. Select the Crop tool, tick Delete Cropped Pixels in the options bar and press Enter twice (CreativePro walks through it). You lose anything outside the frame.
• Delete hidden layers you won't use, from the Layers panel menu (Delete > Hidden Layers). You lose the alternatives you kept around.
• Downsize under Image > Image Size. Halving the width and height leaves a quarter of the pixels, and the detail doesn't come back.

Why the white-layer trick works, and a cleaner way

The most common tip online is to add a white or solid-color layer at the top of the stack before saving, or to hide all layers. Your layers aren't touched, so why does it save space? With Maximize Compatibility on, Photoshop saves a flattened copy of what you see. If you see a white rectangle, the flattened copy is a white rectangle, and that compresses to almost nothing. In effect, the trick turns off Maximize Compatibility for one file.

The numbers agree. In a test Conrad Chavez posted in the comments of a Creative Market article, a 249.2 MB file came to 182.6 MB with a white layer on top and 180.8 MB with Maximize Compatibility off.

The trick has its own costs. You have to hide the layer every time you open the file and remember to show it before saving. In a 2016 Adobe Community thread, one reply objects that thumbnails in Finder, Explorer and Bridge become white squares, and another notes that Lightroom shows the file as white too.

Layersqueeze removes the flattened copy the way Photoshop does with the option off, with no extra layer, then zips the 8-bit layers, the same kind of compression that gave the layered TIFF its extra saving in that test. The file stays a PSD.

The methods side by side

How to reduce PSD file size without Photoshop

You don't need Photoshop for the methods that lose nothing, and you don't need to pay. Layersqueeze is a free tool that runs in your browser: drop in a PSD or PSB file, choose which steps to apply and download a smaller copy. The file is never uploaded. Before offering the download, it reads the new file back and checks every layer's pixels and settings against the original, and your original file is never changed.

Other free tools that come up in searches work differently. psd.imtool.app also runs in the browser and keeps every layer, but it removes only the pasted-document history, from the document and from each embedded smart object; its page says a near-zero result means the file had none. Aspose's online app offers options that keep the pixels, such as recompressing smart object data, and others that don't, such as merging layers and converting to 8 bits. Its page notes that it relies on undocumented parts of the format, so results can be broken. 11zon uploads files to its servers and deletes them after two hours. Aback Tools turns the PSD into a flattened JPEG, PNG or WebP, which is handy for a preview but leaves you without layers.

Shrinking many files at once

Layersqueeze takes several files at a time, and each comes back as its own smaller copy. Inside Photoshop, Stephen Marsh posted a script in an Adobe Community thread that goes through a folder, sets Maximize Compatibility to Never, then opens each PSD and PSB and saves it over the original. That removes the flattened copies but leaves 8-bit layers with run-length compression, and because it overwrites your files, back them up first.

What happens when Photoshop saves the file again

Photoshop rewrites the whole file its own way each time it saves. The layers go back to run-length compression, and the flattened copy comes back if Maximize Compatibility is on. We checked this with one painting from Netflix's open animated film Sol Levante, saved by Photoshop with Maximize Compatibility on:

So Layersqueeze suits files you've finished: archives and backups, cloud storage, files you send to clients, and PSD rewards on Patreon or Gumroad. For files you're still working on, setting Maximize Compatibility to Never keeps part of the saving, and you can run the file through again when the job is done.

Keeping files small as you work

• Set Maximize PSD and PSB File Compatibility to Ask or Never under Preferences > File Handling. Adobe's file format help recommends Ask or Never "if you want to significantly reduce file size". Ask lets you keep the flattened copy for files headed to Lightroom Classic or InDesign.
• Place large source images with File > Place Linked when you don't need them inside the PSD.
• Work in 8 bits unless your edits need 16. Heavy grading and smooth gradients are the usual reasons to stay in 16.
• Once the framing is final, crop with Delete Cropped Pixels ticked, and delete layers you're sure you won't need.