Compress PDF
Reduce the size of large, scanned or image-heavy PDFs so they're easy to email and upload. Everything runs in your browser — your document is never uploaded.
To compress a PDF, add your file, pick a compression level, click Compress, and download the smaller PDF — processed entirely in your browser with no upload.
Drop your files here, or choose files
Up to 100 MB per file · batch supported
Zero Server Uploads
Files process in local RAM
Instant WASM Speed
No waiting queues or lags
Unlimited Batching
Convert files without limits
Suggest a Feature or Improvement for Compress PDF
Need custom options, higher limits, or extra format support? Let our engineering team know!
How to use Compress PDF
- 1Add the PDF you want to shrink.
- 2Choose a compression level and image quality.
- 3Click Compress PDF; each page is re-rendered and rebuilt locally.
- 4Check the before/after size, then download the compressed PDF.
How it works
Add your PDF, choose a compression level and quality, and each page is re-rendered as a compressed image and rebuilt into a smaller PDF — all on your device. You'll see the before and after sizes for each file.
This approach is especially effective on scanned documents and PDFs full of photos.
What to expect
Because compression works by rasterising each page, the text in the output becomes part of the page image and is no longer selectable or searchable. That's the trade-off for the size reduction, and it's why this is ideal for scans rather than text documents.
For text-only PDFs that are already small, compression may not help — the tool shows “no gain” honestly rather than producing a larger file you didn't want.
Why compress locally
Uploading a confidential PDF to a compression service defeats the point of keeping it private. Here the document never leaves your device.
Lower the quality slider or pick a stronger compression level for smaller files; raise them to keep more detail.
Format comparison
| PDF type | Typical saving | Why |
|---|---|---|
| Scanned / image-heavy | Large (often 40–80%) | Embedded images are downsampled and re-encoded |
| Photos in slides/reports | Moderate to large | High-res images shrink to screen resolution |
| Pure text / vector | Small | Text is already compact; little to remove |
How much a PDF shrinks depends almost entirely on how many high-resolution images it contains.
Input & output compatibility
Accepts
- Any PDF (text, images, scans)
Produces
- Smaller PDF at your chosen quality level
Compression mainly targets embedded images — text and vector graphics stay crisp. Lower quality = smaller file with softer images.
Real file-size examples
Savings vary by content, so pick a quality level to match the goal:
What to expect
If a text-only PDF barely shrinks, that's normal — there's little to compress. The dramatic savings come from PDFs full of photos or scanned pages.
Common problems & solutions
Text looks fuzzy after compressing
Text should stay sharp — if it doesn't, your PDF is a scanned image of text. Use a higher quality setting, or run OCR before compressing.
File barely got smaller
It's probably already text/vector-based with few images. There's simply less to remove — that's a good sign it was efficient to begin with.
Need a specific target size (e.g. under 5 MB)
Step the quality down and re-check the size; image-heavy PDFs reach small targets easily, text-heavy ones may already be under the limit.
Is this private?
This PDF compression runs entirely in your browser using the built-in canvas and WebAssembly engine. Your files are read from local memory, processed on your own device, and never uploaded to a server.
Because nothing leaves your machine, there is no upload wait, no queue, and no copy of your image sitting in someone else's storage. Closing the tab discards everything — we keep no logs of the files you open and have no account system that could retain them.
That also means it works offline once the page has loaded, and there is no per-file limit imposed by an upload quota — the only ceiling is your device's available memory.
Frequently Asked Questions
Are my images uploaded to a server?
No. Every conversion runs locally in your browser using your device's own processor. Your images never leave your computer or phone, and nothing is stored on our servers.
Will the text still be selectable after compressing?
No. This tool compresses by rendering each page to an image, so text becomes part of that image. It's designed for scanned and image-heavy PDFs where size matters more than selectable text.
How much smaller will my PDF get?
It depends heavily on the content. Scanned and photo-heavy PDFs often shrink dramatically; PDFs that are already just compact text may not shrink much, and the tool will tell you honestly.
Is there a file size limit?
The practical limit is your device's memory rather than a fixed cap. Very large documents use more RAM because each page is rendered before being re-encoded.
Is it free, and are there limits?
It's completely free with no account required. Because processing happens on your device, there's no per-file upload limit — the practical ceiling is your device's available memory. You can batch many files and download them as a single ZIP.