How to compress a PDF
- Choose the PDF you want to make smaller.
- Pick a level or Target size. Start with Recommended for a general shrink. Use Target size when a form has a fixed KB or MB limit.
- Press Compress PDF. You see the original size, the new size and the percentage saved before you download.
If the result is not smaller, keep your original file. That usually means the PDF was already efficient, which is common for documents exported from Word or Google Docs that contain mostly text.
How to compress a PDF to 100KB or 200KB
- Open this page and choose your PDF (or use a deep link such as ?target=200).
- Select Target size and pick 100 KB, 200 KB, 500 KB, 1 MB, or type a custom KB value.
- Press Compress PDF. The tool tries Basic first, then steps down resolution and JPEG quality until the file is at or under your target.
- Check the result line (for example “2.4 MB → 186 KB, target 200 KB”) and download if it fits.
If even the smallest setting is still over the limit — common with many pages of photos — the tool shows the smallest size it reached and suggests Split PDF or removing pages with the PDF Editor. It never claims success when the file is still over the target.
What each level does
- Basic rewrites the file with compact object streams and drops unused data. Nothing on the page changes and text stays searchable, but savings are modest, often 0 to 20%.
- Recommended redraws each page as a JPEG image at about 144 dots per inch with good quality. Scanned documents and photo-heavy PDFs often shrink by 50 to 90%. The page looks the same on screen and prints well on a normal office printer.
- Strong uses about 96 dpi and a lower JPEG quality for the smallest file. It is fine for reading on screen and for upload forms with tight limits, but small text may look soft when printed.
- Target size aims for a KB or MB limit you choose. It keeps the largest result that still fits, and stays honest if the limit cannot be reached.
Important: Recommended, Strong and most Target size runs convert pages to images, so in the new file you cannot select, copy or search the text, and links stop working. Keep your original as the master copy and send the compressed copy. A Target size run that succeeds with Basic alone keeps text selectable.
Why PDFs get so big
Most of a large PDF's size comes from images. A phone scan saved at full camera resolution can be 3 to 5 MB per page, even though a page only needs a fraction of that to be readable. Embedded fonts add more, especially when every font is fully embedded. Text and vector drawings are tiny by comparison. That is why redrawing image-heavy pages at a sensible resolution saves so much space, while text-only documents barely change. Our guide on how to reduce PDF file size explains more ways to make small PDFs from the start.
Typical size limits
Many email services cap attachments at around 20 to 25 MB, and many upload portals for jobs, visas, banks and universities accept only 1 to 5 MB per file. If one compressed file is still too big, split it into parts with Split PDF. If you are building a PDF from photos, JPG to PDF lets you choose A4 or Letter pages, which also keeps the file reasonable.
| Target | Often used for | Rough fit |
|---|---|---|
| 100 KB | Very tight single-document upload boxes | Depends on content; often one short scanned page in greyscale |
| 200 KB | Small form uploads and profile documents | Depends on content; a short scan or a couple of light pages |
| 500 KB | Common mid-range portal limits | Depends on content; several scanned pages at modest resolution |
| 1 MB | Many job, visa, bank and university forms | Depends on content; a short pack of scans or a photo-light PDF |
Limits change by service, so always check the form you are uploading to. Named portals are not listed here because their rules vary.
How this tool works
This tool runs entirely in your web browser using two well-known open-source libraries: pdf-lib, which creates and edits PDF files, and Mozilla's PDF.js, the engine Firefox uses to display PDFs. Both are hosted on our own site, so your browser does not contact any other service while you work. Because the files never leave your device, the tool works for private documents such as contracts, bank statements and ID scans, and it keeps working even on a slow connection once the page has loaded. Very large files depend on your device's memory: a modern phone can usually handle a few hundred pages, and a computer can handle much more.
Want the full explanation? Read our guide: How to reduce PDF file size without losing quality.
More guides on this topic:
Frequently asked questions
How do I compress a PDF to 100KB?
Choose your file, select Target size, pick 100 KB (or open this page with ?target=100), then press Compress PDF. The tool tries to get at or under 100 KB and shows the before and after sizes. If it cannot reach 100 KB, it shows the smallest size it got and suggests splitting the file or removing pages.
How do I compress a PDF to 200KB without losing quality?
Use Target size with 200 KB. The tool first tries Basic, which does not change how pages look. If that is still too large, it redraws pages as images at lower resolution and JPEG quality until the file fits. Below a certain size, pages soften and text is no longer selectable — that is the trade-off for a hard KB limit.
Why can't my PDF get under 100KB?
Usually the file has too many pages or photo-heavy scans. Even at the lowest setting, each page needs some bytes. Split the document with Split PDF, remove unneeded pages in the PDF Editor, or scan in greyscale at a lower resolution and try again.
Is my file uploaded?
No. Compression runs entirely in your browser. The PDF never leaves your device and is not sent to our servers.
How much can a PDF be compressed?
It depends on the content. Scans and photo-heavy PDFs often become 50 to 90% smaller with the Recommended level. Text-only PDFs may only shrink a little, because text already takes very little space.
Will compressing a PDF reduce the quality?
The Basic level does not change how pages look. Recommended, Strong and most Target size runs redraw pages as images at a lower resolution, which looks the same on screen but can soften very small print, and the text is no longer selectable.
Can I compress a password-protected PDF?
No. If you know the password, remove it first with Unlock PDF, or print the document to a new PDF if you are allowed to, then compress the new copy.