Optimize PDF
What does Compress PDF do?
Compress PDF reduces file size in the browser by rasterizing each page to a JPEG at a chosen quality. You can pick smaller file, balanced, or higher quality. Page count and visual appearance are kept at that quality. Selectable text, forms, links, vector detail and metadata are not kept. Already optimized files may shrink only slightly.
How to use Compress PDF
- 1Choose one PDF
Open Compress PDF and select a single PDF. Unlock protected files first. The interface accepts one PDF per task.
- 2Pick a quality preset
Choose smaller file, balanced, or higher quality. Smaller file uses a lower JPEG quality and scale. Higher quality keeps more visual detail and a larger file.
- 3Compress locally
Each page is rendered, encoded as a JPEG, and placed on a new PDF page of the same size. This is raster compression, not object-level PDF optimization.
- 4Compare size and clarity
Download the compressed PDF and zoom into small type, photos and line art. If text looks soft, choose higher quality or keep the original for archival use.
Supported files and limits
- Output format: PDF
- Input: PDF
- Output options: smaller file; balanced; higher quality
- one PDF per task in the interface; already optimized files may shrink only slightly
- Files stay on this device and are removed when you close the page.
Pages are rasterized, so the result is a visual PDF rather than a text-preserving rewrite. Selectable text, forms, links and vector detail are lost. Already optimized files may become only slightly smaller.
What the output keeps
- page count
- visual page appearance at the selected quality
The page count stays the same. Each page keeps the original width and height, and the visual appearance at the selected JPEG quality and scale.
What may change or be lost
- selectable text
- forms
- links
- vector detail
- metadata
Because pages are drawn as images, you cannot search, copy or fill the compressed file the way you could in the source. Vector line work is flattened. Original metadata is replaced by the local compression producer tag.
When not to use this tool
Do not use Compress PDF when you must keep selectable text, form fields, hyperlinks or print-quality vectors. It is the wrong tool for legal archives that require a text layer, and it will not magically shrink a file that is already mostly JPEG images.
If processing fails
Encrypted or damaged PDFs should be unlocked or repaired first. If compression finishes but the file is larger, the source was probably already image-heavy; try the smaller-file preset or split the document. Very large page counts can exhaust memory — process a shorter extract instead.
Privacy boundary
Compression runs in this browser. The source PDF is not uploaded to a PDF Smart Kit application server. The compressed file exists in memory until you download it or close the page.
Testing evidence
Last tested: · Test browser: Desktop Chrome via Playwright Chromium · Product version: 1.0.0
Sample: Multi-page PDF containing text and images · 2 pages
What was checked
- The download is a valid PDF.
- Page count matches the source.
- Pages remain visually readable at the selected quality.
Known failures and limits
- Compression rasterizes pages, so selectable text, forms, links and vectors can be lost.
- Already optimized files may shrink only slightly.