How to compress a PDF to a specific size
- Select or drop the PDF.
- Pick the target size (e.g. 200 KB or 1 MB) or enter a custom size in KB. Tick Grayscale for text scans if you need it even smaller.
- Click “Compress PDF”. bopdf tries lossless compression first; if that is not enough, it tests several quality levels and keeps the best one under your limit.
- Check the reported size and download.
Why upload forms ask for 100 KB, 200 KB or 1 MB
Government portals, job applications, university admissions and exam registrations often reject files above a fixed size — 100 KB or 200 KB for ID scans and certificates, 1–2 MB for application documents, 5–10 MB for email attachments. Generic “compress” buttons do not know your limit, so you end up compressing again and again. Here you set the limit once.
How it works — and what to expect
First bopdf rewrites the PDF losslessly. If the file is still too big, pages are re-rendered as JPEG images and bopdf runs a quick search over resolution and quality levels (from about 150 DPI down to 30 DPI) to find the highest quality that still fits. Pages turned into images lose selectable text, so use the largest target your form allows.
Realistic limits: a one-page scan fits easily in 100 KB; a 10-page colour scan usually needs 500 KB–1 MB to stay readable. If your target is impossible without making text unreadable, bopdf says so and gives you the smallest version instead of a blurry mess. Tip: split long documents or delete unnecessary pages first.
🔒 Your files never leave your device
bopdf processes your documents locally with JavaScript (pdf-lib and Mozilla pdf.js) inside your browser tab. Your PDF is never uploaded, stored or seen by us — you can even disconnect from the internet after the page loads and the tool keeps working. When you close the tab, everything is gone.
Frequently asked questions
Can I compress a PDF to exactly 100 KB?
bopdf aims to get as close as possible under the limit, not exactly to it — forms accept anything up to the limit, so smaller is fine.
Why is my compressed PDF blurry?
The target was very small for the number of pages. Choose a larger target, use Grayscale for black-and-white documents, or remove pages you do not need.
Does it work on iPhone and Android?
Yes, in Safari or Chrome. Very long documents take longer on phones because every attempt renders each page.
Is my PDF uploaded?
No. Every attempt runs in your browser; the PDF never leaves your device.
Are my files uploaded to a server?
No. Everything happens in your browser on your own device. Files are never sent over the internet, which makes bopdf suitable for confidential documents.
Is there a file size limit?
There is no fixed limit, but very large files (hundreds of MB) depend on your device memory. On phones, files up to about 100 MB usually work well.