PDF Size Limits for Email, Chat Apps, AI Tools and Upload Portals

AI assistant file limits: ChatGPT, Claude, Gemini

AI assistants take large files, from 50 MB in Copilot to 512 MB in ChatGPT. Length is the limit you're more likely to hit: ChatGPT caps text at 2 million tokens, and Claude reads only the text of PDFs over 100 pages. For a long document, split it into parts.

Email attachment size limits

Email limits count every attachment in a message together. Files also grow by about a third when they're encoded for sending, and the receiving server may count that bigger size. Our guide to shrinking a PDF for email covers the details.

WhatsApp, Telegram and chat app file limits

Chat apps allow far bigger files than email. WhatsApp and Telegram take documents up to 2 GB. The tight one is Discord, where free accounts can send 20 MB.

Resume, job site and seller upload limits

Resume limits are small, but a one- or two-page resume exported from Word is usually well under them. If yours is too big, shrink it with Optimize PDF. Hiring systems read the text in your resume, and compressing pages into images would remove it.

School and university upload limits

Canvas takes files up to 5 GB and Turnitin up to 100 MB. Blackboard and Moodle let each school set its own limit, so check your course page. Turnitin rejects scans with no selectable text on similarity checks, so run them through OCR PDF first.

Visa and immigration upload limits

Most visa portals cap each file at 4 to 12 MB. IRCC and Immigration New Zealand take one file per upload slot, so merge related pages into one PDF first. GOV.UK lists file types for UK visa evidence but no size limit.

Government, tax and court filing limits

Tax and benefits portals allow 6 to 25 MB per file. Federal courts each set their own limit, and PACER's Court CM/ECF Lookup lists them all. Some, like S.D.N.Y., require searchable text, so split big filings instead of compressing them into images.

PDF size for Indian exam, ID and tax forms

Indian exam and ID forms want small files, often 50 to 300 KB per certificate (here's why portals set limits this small). Set the exact size with Compress PDF, or use the 200 KB and 500 KB presets. Aadhaar, voter ID and driving licence portals publish no document size.

How to get a PDF under any size limit

Try these in order, and stop as soon as the file fits.

1. 1
   Remove pages you weren't asked forThe smallest page is the one you don't send. Cut extras with Delete PDF Pages before anything else.
2. 2
   Compress to the exact limitOpen Compress PDF, choose Target size and type the limit. The 100 KB, 200 KB, 500 KB and 1 MB pages open with that size already set.
3. 3
   Keep the text if software reads itHiring systems, Turnitin and some courts read the text in your file. Use Optimize PDF for those. It keeps text selectable, though it saves less.
4. 4
   Turn on grayscale for black-and-white pagesA colour scan of a black-and-white page carries colour it doesn't need. Turn on Convert to grayscale in Compress PDF to drop it.
5. 5
   Still too big? Split itIf the site takes more than one file, split the PDF at a natural break, such as one file per document.
6. 6
   Check it before you uploadOpen the result at normal zoom and read every number. After compressing, the compare slider in Compress PDF shows the pages before and after.

Why a PDF under the limit can still be rejected

The size on your screen isn't always the size the site measures. Four common reasons:

• Megabytes are counted two ways. Some sites count 1 MB as 1,000 KB, others as 1,024 KB. Aim about 5% under the limit.
• The limit covers several files. Email counts every attachment in a message together. The IRS, Social Security and HMRC also cap how many files you send at once.
• Email makes files bigger. Attachments grow by about a third when they're encoded for sending, and the receiving server may count the bigger size.
• The cap is pages or words, not bytes. Claude stops at 1,000 pages per PDF, LinkedIn document posts at 300 pages and NotebookLM at 500,000 words per source. A small file can still be too long, so split it into parts.

Does the PDF format have a size limit?

Not one you'll run into. In older PDFs, the file's index stores positions as 10-digit numbers, which caps a file at about 10 GB; newer PDFs can go past that. Every limit on this page is set by the app or site, not by the PDF format.

PDF size limits: frequently asked questions

How we check these limits

Every number comes from the service's own help page, rules or official guide. Each row links to that source and shows the month we checked it. Limits change without notice, so if one is out of date, tell us and we'll fix it.