Initializing Secure Environment…
Initializing Secure Environment…
Break a large PDF into pieces that each fit under a size limit. Rather than guessing from an average page size, every part is assembled and then measured; if it comes out over the limit it is rebuilt smaller until it fits. That matters because PDF pages vary enormously in weight — a text page might be 20 KB and a full-page scan 3 MB — so any estimate based on page count alone will overshoot. Runs entirely in your browser.
To split a PDF by file size, set a maximum size per part and let the tool cut the document where it needs to. On ihatepdf, enter a limit in megabytes — 20 for Outlook, 25 for Gmail, often 2 to 5 for upload portals — and each part is built and then measured, shrinking until it genuinely fits under the cap. Download the parts individually or all together as a ZIP.
The obvious approach — divide the file size by the page count and cut every N pages — fails on almost every real document, because pages are not remotely uniform. A report with twenty pages of text and four full-bleed photographs might have four pages carrying ninety per cent of the bytes. Split it evenly and one part sails over the limit while the others are nearly empty. Measuring each part after building it costs a little time and removes the guesswork entirely: the tool starts from an average-based estimate, then shrinks any part that comes out too heavy until it genuinely fits.
Gmail rejects attachments over 25 MB and offers a Drive link instead. Outlook.com stops at 20 MB, while many corporate Exchange servers are configured far lower — 10 MB is common. Government and university upload portals are frequently the strictest, capping submissions at 2 to 5 MB. Because email attachments are base64-encoded, a file occupies roughly 33% more in transit than on disk, so a 24 MB file can still bounce off a 25 MB limit. Leaving a margin of ten to twenty per cent below the stated cap avoids a frustrating round trip.
The obvious approach is to divide the file size by the page count and cut every N pages. It fails on almost every real document, because pages differ in weight by two or three orders of magnitude. A twenty-page report with four full-bleed photographs might carry ninety per cent of its bytes in those four pages; split it evenly and one part sails over the limit while the others are nearly empty. This tool starts from an average-based estimate, builds the part, then measures it — and rebuilds it smaller if it came out heavy. That costs a little time and removes the guesswork completely, which is the difference between a part that fits and one that bounces.
Gmail refuses attachments over 25 MB and substitutes a Drive link. Outlook.com stops at 20 MB, but corporate Exchange is frequently configured far lower — 10 MB is common and 5 MB is not rare. Government and university submission portals are usually the strictest of all, often capping uploads at 2 to 5 MB. Because attachments are base64-encoded for transport, a file occupies roughly 33 per cent more in transit than it does on disk, which is why files that look comfortably under a limit still get rejected. Leaving ten to twenty per cent of headroom below the stated cap avoids the round trip.
Parts come out numbered in order — document-01.pdf, document-02.pdf and so on — so they sort correctly in a mail client and in a file listing, and the recipient can tell at a glance whether they have all of them. It is worth saying in the email how many parts there are; the commonest failure with a split document is not a corrupted file but a recipient who never realised part three existed. If the recipient needs the document whole again, Merge PDF puts the parts back together in order with nothing lost, because splitting never altered the pages in the first place.
Set the limit slightly below your mail provider's cap to leave room for encoding overhead — 20 MB for a 25 MB Gmail limit, for example. Attachments are base64-encoded in transit, which adds roughly a third to the transmitted size, so a little headroom is wise.
Each part is measured after it is built and rebuilt smaller if it exceeds the cap. The one exception is a single page that is itself larger than the limit — it cannot be split further, so it is written out and clearly flagged as being over.
It is written as its own part and marked "single page above the limit". Compress that page with the Compress PDF tool first if it must fit — a full-page scan usually shrinks by 50–70%.
Often, yes. If the document is large because of scanned images, Compress PDF may bring the whole thing under your limit in one step and keep it as a single file. Split when the document is genuinely too large to compress far enough, or when the recipient needs it in sections.
No. Pages are copied across untouched — nothing is re-compressed or rasterised. The parts together contain exactly the original pages.
At whatever page boundary keeps each part under the limit. If you need cuts at chapters or specific pages instead, use Split by Bookmarks or the main Split PDF tool.
No. Everything runs in your browser, which also means there is no server-side cap on how large a PDF you can split.
Compress first if the document is large because of scans or photographs — it often brings the whole thing under the limit and keeps it as one file, which is what recipients prefer. Split when compression cannot get there, when the document is genuinely enormous, or when the recipient wants it in sections anyway.
Below the stated cap, not at it. Email attachments are base64-encoded in transit, which inflates them by roughly a third, so a 24 MB file can still bounce off a 25 MB limit. Twenty megabytes for Gmail and fifteen for Outlook are safe working numbers.
Because pages are not the same weight. A page of text might be 20 KB and a full-page scan 3 MB, so a part of six text pages and a part of two scanned pages can be the same size on disk. Parts are built to a byte budget, not a page count.
No. Pages are copied across exactly as they are — nothing is re-encoded, re-sampled or rasterised. The parts together contain precisely the original pages.
It cannot be divided further, so it is written as its own part and clearly marked as over the limit. Run that page through Compress PDF if it has to fit — a full-page scan usually loses 50 to 70 per cent.
No server limit, because there is no server. The practical ceiling is your device memory, which on a desktop browser comfortably covers documents of a few hundred megabytes.
Not in this tool — the cuts fall wherever keeps each part under the limit. If you need cuts at chapters or specific pages, use Split by Bookmarks or the main Split PDF tool.
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