Free PDF Tool · Split

Split PDF by Size

Run split pdf by size in your browser. Free, private, no signup — your selected files are processed in your browser and are not uploaded to our server.

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Drop your file here

or click to browse from your device

Accepts: .PDF
How it works: This tool copies whole PDF pages into separate parts based on an approximate target size. It does not compress, rasterize, or reduce quality; a part can exceed the target if one page is larger than the limit.

About this Split PDF by Size

Split a large PDF into multiple PDF parts based on an approximate target size per part. Estimate mode uses a bytes-per-page approximation. Exact mode tries saving chunks and gets closer, but a part may still exceed the target if a single page is larger than the limit. This tool copies whole pages; it does not compress, rasterize, or reduce quality.

Use it for email attachment limits, portal uploads, and sharing large PDFs as smaller whole-page parts. It does not change page quality or make the PDF image-based.

Your privacy is the default. Your selected files are processed in your browser and are not uploaded to our server. This size-splitting operation runs client-side using pdf-lib and JSZip. Closing the tab clears the working session from this page; downloaded files remain on your device.

This tool is free to use with no signup required. Large files may be limited by your browser’s memory and device performance. Part of PDF Tools Base, a privacy-first collection of 161 PDF utilities. Bookmark the page for next time, and explore related tools in the footer below.

How to use the Split PDF by Size tool

  1. Drop your PDF file.
  2. Choose target size per part and splitting method.
  3. Click Process and wait while the tool groups whole pages into parts.
  4. Download the ZIP of split PDF parts.

Why use PDF Tools Base?

100% Browser-Based

Split PDF by Size processes selected files in your browser. Your selected files are processed in your browser and are not uploaded to our server.

No Server Upload, No Signup

Your selected files are processed locally in your browser. No account, no server upload, no email needed.

No Watermark Ever

Outputs are clean. We never stamp our brand or a paywall watermark on your files.

Free to Use

No accounts and no signup. Use the tool as much as you need within reasonable browser limits.

Works on Every Device

Windows, Mac, Linux, iPhone, iPad, Android, Chromebook. Any modern browser.

Built on Open Source

Powered by pdf-lib and JSZip for browser-side PDF splitting and ZIP output.

Common uses for split pdf by size

Email attachments

Most providers cap attachments at 25MB.

Web upload limits

Government portals often enforce 200KB-2MB caps.

Faster sharing

Smaller files send and download faster.

Portal uploads

Upload parts separately when a portal limits each file size.

Mobile data

Smaller parts are easier to email or upload within size limits.

Batch sharing

Share large documents as manageable whole-page parts.

Frequently asked questions

Is Split PDF by Size safe to use?

Yes. Everything happens in your browser. Your selected files are processed in your browser and are not uploaded to our server. Closing the tab clears the working session from this page; downloaded outputs remain on your device until you delete them.

Do I need to register or sign in?

No. No account, no email, no sign-up. Open the page and start using the tool immediately. Free to use, no signup needed.

Is there a watermark on the output?

No. PDF Tools Base never adds a watermark or branding to your output. Your final file is clean — just what you produced from the original.

Is there a file size limit?

There’s no fixed limit. Since processing uses your device’s memory, phones may struggle with PDFs over 50–100MB; desktops may handle larger PDFs but can still fail on very large or complex files. Large PDFs may be slow or fail depending on browser, device memory, page count, PDF complexity, and selected part size — try a smaller PDF or a desktop browser.

Does this work on mobile devices?

Yes. The tool works on all modern mobile browsers: Chrome on Android, Safari on iOS, Firefox, Edge, Brave. The drag-and-drop also accepts files from your phone’s file manager.

Will each part be exactly under the target size?

Not always. PDF pages cannot be split inside a page. If one page is larger than the target, that part can exceed the target. This tool copies whole pages into separate PDF parts; it does not compress, rasterize, or reduce quality.