Compress PDF to 200KB or 100KB on Android, Offline

Job portals, university admissions, visa and government forms often accept PDFs only up to a fixed size: 100KB, 200KB, 500KB or 1MB. A two-page document scanned on a modern phone can easily be 4MB, so the upload fails with "file size exceeds limit." This guide explains why PDFs get that big, how to compress a PDF on Android without uploading it to a website, and what to do when a single compression pass still leaves you over the limit.

Why Your PDF Is So Big

A PDF made from text, such as a Word document saved as PDF, is usually tiny: a few pages of text often take well under 100KB. The problem is scanned PDFs. Every scanned page is really a photo inside a PDF wrapper, and phone cameras take very large photos.

• Resolution: a 12MP phone photo is about 4000×3000 pixels. A printed A4 page only needs about 1240×1754 pixels at 150 DPI, roughly a fifth of that.
• Colour: a full-colour page stores three colour channels. A grey or black-and-white page needs far less data.
• Image quality: JPEG images saved at very high quality keep detail you cannot see on a form.
• Page count: size grows with every page. A 6-page scan is roughly six times a 1-page scan.

Compression works by shrinking those images: lowering resolution and image quality, which is why it can cut a scanned PDF by 70–90% while text-only PDFs barely change.

How to Compress a PDF on Android

These steps use PDF Zipper, a free PDF app that compresses files on your phone instead of uploading them.

1. Install PDF Zipper from Google Play and open it. No account is needed.
2. Tap Compress PDF and choose the PDF from your phone.
3. Pick a level: Low, Medium or Maximum compression.
4. Check the estimated size the app shows before saving. If it is above your limit, choose a stronger level.
5. Save, then open the file once to make sure the text is still readable.

Everything runs on the device, so the file never leaves your phone. That matters for documents like ID cards, certificates and bank statements.

Hitting 1MB, 500KB, 200KB and 100KB

How far you can go depends on what the PDF contains. As a rough guide for scanned A4 pages:

These are estimates, not promises. A page full of photos compresses less than a page of typed text. Always check the estimated size before saving.

Still Too Big? 5 Fixes That Work

1. Rescan in black-and-white or grey. In PDF Zipper's scanner, the Grey or Black & White filter makes text pages dramatically smaller than colour. Most forms do not need colour.
2. Lower the image quality when creating the PDF. If you are making the PDF from photos, the Image to PDF tool lets you choose image quality. See our JPG to PDF guide.
3. Split the PDF. If the portal allows several uploads, use Split PDF to save each page separately; each page is then well under the limit.
4. Remove blank or extra pages before compressing. The editor can delete pages.
5. Crop tightly. Scanning only the document, not the table around it, removes wasted pixels.

Online Compressors vs Offline Apps

Websites are convenient on a computer, but the documents people compress most often are exactly the ones you would rather not upload: passports, national ID cards, marksheets and payslips. If you do use a website on public WiFi, at least make sure the connection is encrypted; see VPN and public WiFi security.

How to Check the Final Size

• Open the Files app, long-press the PDF and tap Details or the ⓘ icon.
• Remember that 1MB is 1024KB. A file shown as "0.21MB" is about 215KB and may still be rejected by a 200KB limit.
• Some portals count in decimal (1MB = 1000KB). Aim a little under the limit to be safe.

Frequently Asked Questions

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