Split a PDF for Email Attachments
Most email providers cap attachments at 10-25MB, and recipients with stricter corporate inboxes may see anything over 10MB bounce.
Split into email-friendly file sizes
No attachment size workarounds needed
Compress after splitting as an option
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Embed code
<iframe
src="https://www.fixtools.io/pdf/pdf-splitter?embed=1"
width="100%"
height="780"
frameborder="0"
style="border:0;border-radius:16px;max-width:900px;"
title="PDF Splitter by FixTools"
loading="lazy"
allow="clipboard-write"
></iframe>Attribution-friendly: a small "Powered by FixTools" link appears in the embed footer.
Gmail and Outlook attachment limits, when to split versus compress, and sending multi-part PDFs
Email attachment size limits vary by provider and account type. Gmail allows attachments up to 25MB per message; files larger than 25MB are automatically converted to Google Drive links. Outlook.com caps attachments at 20MB. Yahoo Mail allows 25MB. Microsoft 365 business accounts (Exchange Online) have a default limit of 25MB but administrators can raise this to a maximum of 150MB. Corporate Exchange servers often have lower limits set by IT policy, commonly 10MB or 20MB. Knowing your recipient's limit matters, a 22MB PDF that fits within Gmail's 25MB allowance may still exceed your recipient's corporate Exchange server limit of 20MB. When in doubt, target 15MB or less per attachment for maximum compatibility across mail systems.
The choice between splitting and compressing depends on whether the file is over the limit due to high page count or due to embedded image quality. A 50-page text-heavy PDF at 30MB is large because of document volume; splitting it into two 25-page files at roughly 15MB each is the cleaner solution. A 10-page scanned PDF at 45MB is large because of high-resolution images; compressing it from 45MB to 8MB is the cleaner solution because the recipient gets one file rather than multiple parts. The general rule: if the PDF has more than 20 pages and the size comes from volume, split it. If the PDF has 15 or fewer pages and the size comes from images, compress it first and only split if compression alone is insufficient.
When sending a split PDF in multiple email messages, include clear labeling to help the recipient reassemble or manage the parts. Name each file consistently: "Q3_Report_Part1of3.pdf," "Q3_Report_Part2of3.pdf," "Q3_Report_Part3of3.pdf." In the email body, note the total number of parts and the page ranges each covers. Send all parts in the same email thread so the recipient can find them together. If the recipient needs to reassemble the parts, direct them to FixTools PDF Merger, which can combine the parts back into a single document in their browser.
There are a few less obvious factors that change how much room you actually have for an attachment. Email systems base their size limit on the encoded message, not the raw file. MIME base64 encoding inflates binary attachments by roughly 33 percent before transmission, so a 20MB PDF travels as about 27MB of message payload. Most providers publish their limit as the encoded size, which is why a "20MB" file occasionally bounces on a server that advertises a 25MB cap. To stay safe, target raw file sizes that are at least 20 percent below the published limit. Also remember that some receiving systems strip or quarantine attachments based on signature scanning policies, particularly in healthcare, legal, and finance environments. If a previous send has failed silently, ask the recipient to whitelist your sender address or to confirm whether their gateway accepts PDF attachments at all before you split a sensitive document into multiple parts and send it.
How to use this tool
Upload your large PDF and split it by page range or equal-size chunks so each part fits within your email provider's attachment limit. Alternatively, use PDF Compressor to shrink the file without splitting.
How It Works
Step-by-step guide to split a pdf for email attachments:
- 1
Check your email size limit
Gmail allows 25MB per message, Outlook.com allows 20MB, Yahoo allows 25MB, and Microsoft 365 Exchange Online defaults to 25MB but can be capped lower by your IT administrator. Confirm the limit for both your sending account and your recipient's mailbox if known, since the smaller of the two governs delivery.
- 2
Upload your large PDF
Open the FixTools PDF Splitter in any browser and drag the oversized PDF onto the upload area. The file stays in your browser tab, nothing is uploaded to a remote server, so even sensitive financial or legal documents can be split without leaving your machine.
- 3
Split into equal-size parts
Choose the "split every N pages" option and pick a page count that divides your file into parts under the target limit. For a 60MB, 240-page PDF aimed at a 20MB cap, split every 80 pages to produce three roughly 20MB parts. Verify each output file size after download before sending.
- 4
Send parts in separate emails
Attach each part to a separate email message in the same conversation thread. In the subject line, append "Part 1 of N," "Part 2 of N," and so on. In the body, list the page ranges each attachment covers and link the recipient to PDF Merger if they want to recombine them.
Real-world examples
Common situations where this approach makes a real difference:
Accountant
An accountant needs to email a 55MB, 180-page annual financial report to a client whose corporate email has a 20MB attachment limit. She splits the report into 4 equal parts of 45 pages each, producing four files of approximately 13MB each. She sends each part in a separate email with the subject line "Annual Report [Part 1 of 4]" and a note in the body directing the client to the page range covered. She also includes a final summary message linking back to FixTools PDF Merger so the client can rejoin the parts before archiving the report in their internal document management system.
Architect
An architect has a 40MB, 25-page construction drawing set that needs to be emailed to a contractor. The drawing set is large due to high-resolution CAD exports at 600 DPI. Rather than splitting (which would separate related drawings), he runs the PDF through the PDF Compressor first. Compression at medium quality reduces it from 40MB to 9MB, which fits in a single Gmail attachment without splitting. He spot-checks a few pages at 100 percent zoom to confirm that dimension callouts and door schedules remain legible, then attaches the compressed file with a brief note explaining the compression so the contractor knows to request a higher-resolution version if they need to print at full scale.
Legal assistant
A legal assistant needs to email a 65-page, 38MB deposition transcript to three attorneys. Gmail's 25MB limit prevents attaching the full file. She splits it into two parts: Part 1 covers pages 1-35 (18MB) and Part 2 covers pages 36-65 (20MB). Both parts are under 25MB and sent in two separate emails. She notes the page ranges in each email subject line and CCs the case docket address so both halves are filed under the same matter number. Because the firm's outbound gateway encodes attachments with base64, she leaves a margin of about 5MB under the limit on each part to avoid encoded-size bounces.
Non-profit coordinator
A non-profit coordinator needs to send a 30MB grant application PDF package via a state agency's email portal that has a 10MB attachment limit. She splits the application into 4 parts by section: cover letter and executive summary (pages 1-8, 4MB), program description (pages 9-21, 9MB), budget and financials (pages 22-35, 10MB), and attachments (pages 36-50, 7MB). Each part stays under the 10MB limit. She names the files with the agency's required convention (Org_GrantID_Section_PartXofY.pdf) and sends each part as a separate submission email, retaining bounce-back receipts as proof of timely filing in case the agency questions whether any section arrived before the deadline.
Pro tips
Get better results with these expert suggestions:
Try compression before splitting, one file is always better than multiple
A recipient who receives one compressed PDF has a simpler experience than one who receives three parts and needs to reassemble them. Before splitting, run your PDF through the FixTools PDF Compressor. For scanned documents and image-heavy PDFs, compression often achieves 60-80% size reduction. A 45MB scanned report may compress to 7MB, eliminating the need to split entirely. Only split if compression alone cannot bring the file under the email limit, or if the file is text-heavy and already optimized so further compression would harm legibility.
Calculate part sizes before uploading
Divide your file size by the number of parts you plan to create before uploading. A 60MB PDF split into 3 parts averages 20MB per part, within Gmail's 25MB limit but over Outlook's 20MB limit. If you are unsure of the recipient's limit, target 15MB per part for safe delivery across all common email systems. Adjust your pages-per-part value accordingly.
Name split files with part numbers and page ranges
Use a naming convention like "ProjectReport_Part1of3_Pages1-45.pdf" rather than the default "part_01.pdf." Descriptive names help the recipient track which parts they have received and which pages each covers. When the recipient later needs to reassemble the parts, clearly named files make the merge order obvious without having to open each file to check.
Use a cloud link for very large files instead of splitting
If your PDF is over 100MB and splitting would produce more than 5 parts, consider uploading to Google Drive, Dropbox, or OneDrive and sharing a link instead. Google Drive shares files of any size without size limits. For confidential documents, set the sharing permission to "anyone with the link can view" and include an expiration date. This is often more practical than sending 6+ email attachments.
Frequently asked questions
Related guides
More use-case guides for the same tool:
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