Compress a PSD file online, without losing anything
A lossless PSD compressor that runs in your browser. It removes the metadata Photoshop piles up over time and leaves every layer and pixel exactly as it was.
Most “compress PSD online” tools do one of two things: they re-encode your pixels with a
quality slider, or they quietly export a flattened JPEG and hand it back with a
.psd extension. Either way, the file you get is not the file you had. This
one is different. It changes nothing you can see and removes the one thing that makes
Photoshop files balloon: an ever-growing metadata log called
DocumentAncestors.
Drop a file below. If it has the bloat, you will see a large saving in a few seconds. If it does not, you will see a small one, and the guide further down explains what to do next.
Lossless versus lossy PSD compression
| Approach | Layers kept | Pixels unchanged | Typical result |
|---|---|---|---|
| Metadata stripping (this tool) | Yes | Yes, byte-identical | 0% to 99%, depends on file history |
| ZIP or 7z archive | Yes | Yes | 5% to 20% |
| “Lossless” online compressors that re-pack RLE channels | Usually | Usually | Small, and the file is uploaded to their server |
| Quality-slider compressors | Sometimes | No | Large, with visible artefacts on re-edit |
| Convert to JPG or PNG | No | No | Very large, but it is no longer a PSD |
What this compressor actually removes
Whenever you paste or place content from one Photoshop document into another, Photoshop appends the source document’s ID to an XMP list stored in the file. It never removes old entries, and every embedded smart object keeps its own copy. On files used as templates or passed around a team, that list can be bigger than the artwork. The engine behind this page rewrites the file with the list removed from the main document and from each smart object, recalculates section lengths, and copies everything else through untouched.
Removed
photoshop:DocumentAncestorsrdf:Bag/rdf:lientries inside it- Same field inside embedded smart objects
Untouched
- Every layer, group, mask and effect
- Smart objects, linked files, adjustment layers
- ICC profile, guides, slices, author and copyright metadata
- The composite preview and all pixel data
Privacy: no upload, by design
PSD files are often client work under NDA. Uploading a 900 MB layered master to a compression website is slow and, for many studios, not allowed. This tool has no upload endpoint. The WebAssembly engine is about 20 KB, loads once, and processes the file in a Web Worker on your machine. You can disconnect from the network after the page loads and it will still work.
If the saving is small
A near-zero result means your file has no ancestor bloat and the size is real. In that case the honest options all cost something. In order of least to most destructive:
- Turn off Maximize Compatibility in Preferences → File Handling. Saves the flattened preview, usually 10 to 40 percent.
- Convert 16-bit documents to 8-bit if you are not doing heavy colour grading. Halves pixel data.
- Replace embedded smart objects with linked ones for large placed photos.
- Rasterize smart objects that are final, and merge finished groups.
- Downsample if the document is larger than its destination needs.
The full comparison of PSD size reduction methods has a table of what each one loses.
Compressing PSD files in bulk
The browser tool processes one file at a time. The same engine is available as an open-source command-line utility, psd_ockham, which takes a folder and writes cleaned copies next to the originals. It is the right choice for asset pipelines, build servers, and archives with thousands of files.
Drop a PSD above to compress it now. Free, no upload, no signup.
Real numbers: before and after
The first row is a file we measured with this exact engine. It took 1.4 seconds on a laptop. The other rows are cases reported by Photoshop users on Adobe’s forums after removing the same metadata field.
| File | Before | After | Saved |
|---|---|---|---|
| Game art, 1920×1080, RGB 8-bit, many smart objects | 902 MB | 254 MB | 71.8% |
| Retouched photo passed between editors (Adobe Community) | 65 MB | 110 KB | 99.8% |
| Reused PSD template, images placed repeatedly (Adobe Community) | 100 MB | 7 MB | 93% |
Your result depends entirely on how much ancestor history the file carries. A PSD created in one sitting and saved once may shrink by only a few kilobytes. A file that has been a template for two years can lose most of its size.
Step by step
- Open the compressor. Open psd.imtool.app in Chrome, Firefox, Safari or Edge on a desktop. There is nothing to install and no account.
- Add your PSD or PSB. Drag the file onto the drop zone or click to choose it. The file is read locally and never uploaded.
- Let it run. The engine removes bloated DocumentAncestors metadata from the document and its embedded smart objects. A 900 MB file takes a few seconds.
- Check the result and download. Compare the before and after sizes. Download the compressed copy; your original stays as it was.
FAQ
Is this a lossless PSD compressor?
Yes, in the strict sense. It removes a metadata log that nothing renders, and it leaves every pixel, layer, mask and effect byte-identical. It does not re-encode image data, so it cannot degrade quality and it also cannot shrink a file whose size is real pixel data.
Why do other online PSD compressors ask for a quality slider?
Because they recompress or downsample pixel data, or convert the file to a JPEG that merely keeps the .psd extension. A slider means information is being thrown away. Check the output in Photoshop: if layers are gone or the file is a single flattened layer, it was not compressed, it was exported.
Can I compress a PSD by zipping it?
Only a little. Photoshop already RLE-compresses channels, so ZIP typically saves 5 to 20 percent. ZIP does nothing about the ancestor metadata, because that text compresses but remains in the file when unzipped.
Does the file get uploaded?
No. The whole process runs in your browser in a Web Worker using WebAssembly. Nothing is sent over the network. The file is streamed from disk and the result is written to disk, so there is no practical size limit; multi-gigabyte PSBs work.
What if my file barely shrinks?
Then the size is real image data, not metadata. Look at bit depth, embedded smart objects, resolution and Maximize Compatibility. The guide on reducing PSD size lists what each option costs.
Does it work for PSB?
Yes. PSB files of any size work in the browser; the engine streams them rather than loading them into memory. A 3 GB PSB takes a few seconds.