Split a large PDF into files under a target size
WhiskFile Split PDF by File Size is a free online tool to split a large PDF into files under a target size. Files are processed entirely in your browser — nothing is uploaded to any server.
Quick Answer
Split a large PDF into files under a target size. WhiskFile's Split PDF by File Size is free, works in your browser, and requires no account. Your files never leave your device — all processing happens locally.
Upload your PDF
Upload the large PDF that exceeds your email attachment or upload limit. If it already fits, a green message tells you — no splitting needed.
Set the target size
Choose a preset — 5 MB (small email), 10 MB (most providers), 25 MB (Gmail limit), or 50 MB (large uploads) — or enter a custom size in MB.
Download split files
See the estimated output count, click Split, then download all parts as individual PDFs or a single ZIP file. Oversized parts can be compressed inline.
Max file size: 50 MB (free) · 500 MB (paid). Processing time: ~10s on average. Upload one file at a time.
Split PDF by File Size runs entirely in your browser — no software to install. Works on any device with a modern browser.
Windows & Mac
Chrome, Firefox, Edge, Safari
iPhone & Android
Safari, Chrome mobile
iPad & Tablets
Full touch support
Unlike server-based tools that upload your documents, WhiskFile processes everything locally in your browser. Your files never leave your device — not even temporarily.
No upload required
Files are processed in your browser — nothing is sent to any server
100% private
No server storage, no data collection, no third-party access
Works offline
Once loaded, works without an internet connection
“I merge dozens of reports weekly. WhiskFile handles it instantly — no software to install, no sign-up hassle.”
Sarah Chen
Project Manager
“Splitting contracts by section used to take ages. Now I drag, drop, and it's done in seconds.”
David Kim
Legal Assistant
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Client-side processing
This tool now runs entirely in your browser — files never leave your device.
Result preview & sharing
Preview your processed file before downloading, and share results via a secure link.
It splits a large PDF into multiple smaller files, each under a target file size you choose. This is ideal when a PDF is too large for email attachments, portal uploads, or file sharing limits.
Four presets: 5 MB (small email), 10 MB (most email providers), 25 MB (Gmail limit), and 50 MB (large uploads). You can also enter any custom size from 1 to 500 MB.
Yes. Check the Custom checkbox and enter any value in MB. The tool accepts any size from 1 MB to 500 MB.
No. The tool always splits on page boundaries — no content is ever truncated. Each output file contains complete pages.
The page becomes its own file and is flagged with a warning. You can use the Compress & Download button to re-render it as JPEG images at a lower quality to fit within the target.
Gmail allows attachments up to 25 MB. Use the 25 MB preset to split your PDF into Gmail-ready parts. Outlook limits attachments to 20 MB — use a custom 20 MB target for Outlook.
Yes. Enter 20 as a custom target size (Outlook's limit is 20 MB). Each output file will be under 20 MB.
No. WhiskFile processes your PDF entirely in your browser using pdf-lib. Your files never leave your device — nothing is uploaded to any server.
No. WhiskFile has no file size cap, no page limit, and no task-per-hour restriction. Process unlimited documents for free. Competitors like Sejda limit files to 50 MB and 200 pages.
Yes. Click Download ZIP to get all split parts bundled in a single ZIP file — ideal for attaching multiple parts to an email or uploading in batch.
Try Compress PDF first — it may reduce the file enough to avoid splitting. If compression isn't enough (common for text-heavy or already-compressed PDFs), then split by file size.
WhiskFile offers labeled presets (Sejda has none), compress-and-download for oversized parts (unique), no file size limit (Sejda: 50 MB), no page limit (Sejda: 200), no task limit (Sejda: 3/hour), and processes locally (Sejda uploads to their server).
Yes. Adobe's free online tool doesn't support split-by-size — that feature requires paid Acrobat Pro. WhiskFile offers it free in your browser with no software installation.
Yes. Split PDF by File Size on WhiskFile is completely free with no account required. Free users get 7 tasks per day with files up to 50 MB. There are no watermarks on any plan. Pro plans ($4.99/month) unlock unlimited tasks, 500 MB files, batch processing, and API access.
Yes. Split PDF by File Size runs entirely in your browser using WebAssembly. Your files are never uploaded to any server — they stay on your device throughout the entire process. No data is transmitted, stored, or accessible to WhiskFile or any third party.
Yes. Split PDF by File Size works on any device with a modern browser — iPhone, Android, iPad, tablets, Chromebooks, and desktop computers. No app download required. The interface adapts to your screen size automatically.
Split PDF by File Size accepts PDF files as input and produces PDF output. The maximum file size is 50 MB on the free plan (500 MB for Pro users). There are no page count limits.
See how WhiskFile compares to other PDF tools on features, pricing, and privacy.
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