Compress Images for Email (Free, No Upload)

The attachment numbers that matter

Stay under 2MB for corporate SMTP tolerance; 100-500KB is the comfortable sweet spot for attachments and newsletter embeds. A compressed JPG at 70-80% looks identical for on-screen reading.

Compress for email in one step

1. Open the Compress Image tool.
2. Drop your photo or document scan.
3. Target ~400KB with the quality slider (or 70% and resize to 1200px).
4. Download and attach.

For embedded newsletters, stick to 800px-wide images at 60-70% — most clients strip `width` overrides otherwise.

Documents and contracts

Scanned contracts compress perfectly at 100-300KB and print cleanly. Privacy is built in: nothing leaves your device, which matters for contracts and passports.

Attachment limits and what really gets through

Mail servers enforce hard caps that vary by provider: Gmail allows 25MB per message, Outlook.com 20MB, while many corporate systems still sit at 10MB or even 5MB - and the limit applies to the encoded attachment, which is roughly 33% larger than the file on disk. That last detail is why a 9.5MB photo that looks safely under a 10MB limit still gets rejected.

Practical targets: keep each attachment under 3-4MB for guaranteed delivery, and under 500KB when you are sending several photos or when recipients will forward the message again. For documents and screenshots, compressing to 200-300KB rarely loses anything readable. Test by sending the message to yourself once - if your own provider accepts it, delivery is almost certain, because the sending and receiving limits you will meet in the wild are the ones in this range.