Compress a PDF
Shrink a PDF for email or an upload limit. Pick a level, or type the size you need, like 1 MB, and the page tries the gentlest setting that fits. Processed on your device.
- Nothing is uploaded
- Works offline after first visit
- Open source
- No watermark · limit is your device’s memory; phones hold less
Makes a PDF smaller in four ways: a lossless cleanup, image recompression that keeps text selectable, flattening pages to pictures, or fitting it under a size you type, such as 1 MB or 200 KB. It is free, needs no account and adds no watermark, and your PDFs are not uploaded: everything runs in your browser on your device. The size limit is your device’s memory (phones hold less), and after one visit and a short wait the page works offline; a password-protected PDF needs its unlock engine downloaded once first.
Done
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Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
Compress to a set size: 100 KB, 200 KB, 500 KB, 1 MB, 2 MB
Upload forms often name a maximum size. These pages open this tool already set to that size:
Still too big, or worried about quality?
If one file stays over the limit, split the PDF and send it in parts. To see what each level does to the pages, read how to compress a PDF without losing quality.
A worked example: a scan that must be under 2 MB
Say a portal rejects your 14 MB scanned application and accepts files up to 2 MB. Drop the PDF, choose Fit a file size, type 2 and leave the unit on MB, then press Compress PDF. The page tries a lossless rewrite first, then image compression at falling quality, and flattens the pages to pictures only if nothing gentler fits. The result line says which step worked, for example under 2 MB: images at quality 75. If none fits, it says how small it got and suggests splitting the file.
How it works
- Drop one or more PDFs.
- Pick a level, or choose "Fit a file size" and type the limit. "Recompress images" is the default and keeps text selectable.
- Compare the before and after sizes and download.
In your browser, not on a server
Lossless cleanup rewrites the PDF with pdf-lib using compressed object streams. Image recompression uses pdf.js to find embedded images, re-encodes each one at a lower quality on a canvas, and pdf-lib swaps the new streams in. Flatten renders every page to an image at the resolution you pick. Each mode runs entirely in your browser.
Compared with upload-based tools: PDF compressors online are the most upload-hungry tools there are, because the whole document has to go up before anything happens. Here a 50 MB scan is processed without a single byte leaving your machine.
Verify it yourself. Give the page a short while after one visit to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
How does each level work?
"Lossless cleanup" rewrites the file with compressed object streams; text and images stay identical, so a file that is already compact barely changes. "Recompress images" additionally re-encodes embedded photos at a lower JPG quality and caps their resolution, which is where most of the savings come from in scanned or photo-heavy PDFs. "Flatten pages" renders each page to an image at the resolution you choose. It gives the smallest files for scans but text is no longer selectable.
Can it get a PDF under a set size, like 1 MB, without uploading it?
Yes, and the PDF is not uploaded: it runs in your browser. Choose "Fit a file size" and type the limit in KB or MB. The page tries the gentlest settings first (a lossless rewrite, then lighter image compression that keeps text selectable) and flattens pages to pictures only when nothing else fits. The result says which step it took. 1 MB counts as 1,000,000 bytes, so the file passes however a form counts.
Why did my PDF barely shrink?
PDFs made from text (Word exports, invoices) are already small and consist mostly of fonts and vector data that cannot be compressed further without losing content. Compression helps most on files with large photos or scans. At the lossless and image levels you never get back a larger file than you dropped: the original is kept instead, and the result says so.
How do I compress a scanned PDF?
Use "Recompress images" first: a scan is one large picture per page, so lowering the picture quality is where the savings are, and the file stays a normal PDF. The result says how many images were recompressed; if it says none, use "Flatten pages". If it is still too big, choose "Flatten pages" and lower the resolution, or choose "Fit a file size" and let the page step down for you. Flattening gives the smallest scans, but text is no longer selectable.
Can I compress a PDF on my phone?
Try it. Open this page in your phone's browser and drop the PDF in. The work happens in the page, so a long or image-heavy file can be slow on a phone; if it stalls, try a smaller file or split it first.
Will compressing change my text, links or forms?
"Lossless cleanup" and "Recompress images" keep the text selectable, and in our test a link and a filled-in form field survived both; only the embedded photos change at the image level. "Flatten pages" turns each page into a picture, so text is no longer selectable and links and form fields are gone. "Fit a file size" flattens only when nothing gentler fits, and the result says which step it took.
Is the PDF uploaded to a server?
No. Everything runs in your browser using pdf-lib and pdf.js. That is why there is no upload and no queue.
Do I need an account, and is there a watermark?
No account and no sign-up: open the page and drop a file. Nothing is added to your file, so there is no watermark or logo. It is free, and your files are not uploaded.
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