Compress PDF to 25MB for Gmail
Use the Gmail 25MB preset to keep attachments deliverable. Upload once and PDFThin optimizes first; if it still will not fit, we split into size-safe parts.
Fit-or-split result: get one PDF that fits, or a ZIP of parts under the limit.
Email presets: Gmail 25MB, Outlook 20MB, Outlook.com 25MB, plus custom size.
Private by default: files auto-delete after 60 hours; we don't store document contents in logs.
How it works
Upload
Pick a PDF and a target limit.
Process
We optimize and split as needed.
Share
Download a single file or parts.
Gmail 25MB FAQ
Should I compress or split first?
Start with the email-ready tool; it optimizes first and splits only if needed. For manual control, use split by size.
Where can I check other limits?
See email attachment size limits for Gmail, Outlook, and Outlook.com.
Gmail-ready attachments
Gmail 25MB limit, explained
Gmail allows up to 25 MB of attachments per email, but the message size grows when attachments are encoded for delivery. A PDF that looks under 25 MB on disk can still fail once Gmail adds overhead. That is why a safety margin matters.
PDFThin targets the limit with headroom so your attachment sends on the first try. If your PDF is close to the cap, choose a slightly lower custom target to avoid last-minute errors and retries.
Optimize first, split only if needed
We start with lossless cleanup: remove hidden bloat, optimize fonts, and streamline images where it is safe. Many files shrink without visible changes, so you get the same layout and readability in a smaller package.
If the file still exceeds 25 MB, PDFThin splits it into ordered parts that each fit the limit. You get a ZIP of parts ready to attach, and page order stays intact across the pieces.
Tips for reliable Gmail attachments
For scan-heavy PDFs, Smart quality searches for the highest quality that still fits the limit. It works well for contracts, receipts, and image-heavy reports where text clarity matters.
If you need to send multiple attachments, splitting by size keeps each part comfortably under the cap. Recipients can download each part or merge them later without confusion.
Gmail resources
See the Gmail attachment limit guide for details on size caps.
If your PDF is still large, use split by size or follow the make a PDF under 25MB guide.
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Step-by-step workflow for Gmail 25MB and Outlook 20MB limits.
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