Compress PDF. Smaller file, no upload.
Lower = smaller file, softer pages. Pages are rasterised (text becomes an image and is no longer selectable).
Shrink a PDF without the upload
Most “free” compressors push your document to a server before they touch it. This one does the work entirely on your device. Recompress rasterises every page to a JPEG at the quality you choose and rebuilds the PDF for the biggest possible size reduction, ideal when a scan or image-heavy deck is far too large to email. Optimize losslessly re-saves the file structure with object streams, giving a modest saving while keeping every font, vector and selectable text intact. Pick a preset or dial the JPEG quality yourself, watch the before/after numbers, and download in one click. Instant, fully private, offline-capable once loaded. No sign-up, no size limits, free forever.
How to use the Compress PDF tool
This tool shrinks a PDF in your browser in one of two ways. Recompress renders every page to a JPEG image and builds a new PDF from those images, which saves the most space but makes the text unselectable. Optimize re-saves the original file structure more compactly and keeps text, fonts and vector graphics intact. Use it when a scan or a deck is too large to email or upload.
Step by step
-
Load a PDF
Drop a file on Drop a PDF here, or click the box to choose one. A bar appears with the page count and the file size, and its Clear button removes the file.
-
Pick a compression mode
Under Compression mode, choose Recompress for the biggest saving or Optimize to keep text selectable. The sentence under the buttons explains what the selected mode will do.
-
Choose a quality preset
In Recompress mode, pick Low (about 96 DPI), Recommended (about 120 DPI, the default) or High (about 150 DPI) under Quality preset. Each preset also sets the JPEG quality slider to 0.50, 0.65 or 0.80.
-
Fine tune JPEG quality
Move JPEG quality between 0.30 and 0.90 in steps of 0.05. Lower numbers give a smaller file with softer pages. The slider changes quality only; the render resolution still comes from the preset.
-
Compress
Press Compress PDF. The button reads Working… while it runs. In Recompress mode a progress bar counts through the pages, so long documents take longer; Optimize re-saves the file in a single step.
-
Download the result
When the sizes appear, press Download result. The file keeps your original name with -compressed or -optimized added to it.
Reading the result
- Original and Compressed show the two file sizes, and Reduction shows the saving as a percentage. A plus sign in orange means the new file is larger than the original.
- If the saving is 0.5% or less, the status line says the file is already well compressed and suggests Recompress mode. Otherwise it states how much was saved.
- Recompress places each page image on a page scaled to fit an A4 footprint, turned for landscape pages. Page proportions stay the same, but the paper size can change.
- Before encoding, the longest side of each rendered page is capped at 2,200 pixels, so very large pages come out at a lower resolution than the preset suggests.
Tips and common mistakes
- Try Optimize first for documents that must stay searchable, such as contracts or forms. If the saving is too small, switch to Recompress and accept image only pages.
- Recompress builds a new file from page images, so clickable links, bookmarks, form fields and selectable text do not carry over.
- Low gives the smallest file. Zoom in on the smallest print in the result before you send it, to make sure it is still readable.
- If the result is larger than the original, keep the original. A PDF that is already tightly compressed can grow after Recompress.
- A PDF that needs a password to open shows Could not read PDF. Remove the password in your PDF reader first.
Privacy and limits
The PDF is read, rendered and rebuilt in your browser with pdf.js and pdf-lib, which load from this site. The file is never uploaded and stays in memory only until you press Clear or leave the page. Large files with many pages take longer and use more memory, because every page is rendered in turn.
Everything a PDF compressor should do.
- Recompress for big savings, every page is rendered and re-encoded as JPEG, then a brand-new PDF is rebuilt for the maximum size reduction.
- Optimize and keep text selectable, a lossless re-save keeps fonts, vectors and searchable text fully intact.
- Pick a quality preset, Low, Recommended or High, or dial in your own JPEG quality with the slider.
- See exactly how much you saved with a before/after size comparison and a reduction percentage.
- Download the result in one click, named to match your original file with a clear suffix.
- Stay completely private, no file ever leaves your browser, no account needed, no size limit.
Frequently asked questions.
Is the Compress PDF tool free?
Is it private? Is my PDF uploaded anywhere?
Does it work offline?
What is the difference between Recompress and Optimize?
Why did my file barely shrink in Optimize mode?
Do I need to install anything or create an account?
Published · Last updated .
