How to compress images for email without losing quality
Tomoda HinataTool author & maintainerPublished Apr 17, 2026Updated Apr 26, 202610 min read
Most email providers reject attachments above 20–25 MB and corporate gateways often cap at 10 MB. Resize first, compress to JPG quality 78, strip EXIF, and zip if you have more than three files — a 50 MB folder of phone photos lands under 5 MB with no visible difference.
Tools used in this guide
Why does email attachment size matter so much?
Gmail rejects attachments above 25 MB. Outlook 365 caps at 20 MB by default and many corporate tenants drop that to 10 MB. Even when the send goes through, the recipient's inbox quota counts every megabyte — sending five 30 MB photos burns 150 MB of someone else's storage for one message.
Should I resize before compressing?
Yes. PDF and email viewers rarely render above 1920 px wide on desktop or 1280 px on phones, so a 4032 px iPhone photo is 4× larger on disk than it needs to be at the displayed size. Resize first, compress second — the resize pass alone typically removes 70–80% of the file size before the codec even runs.
What JPG quality should I pick?
Quality 78 is the sweet spot for photographs. Below 70 you start seeing posterisation in gradients (sunsets, skin) and 8×8 block artefacts on flat areas. Above 90 the bytes climb sharply with no visible improvement. PNG screenshots with text should usually be re-saved as JPG at quality 90 — the file shrinks 5–10× and Microsoft Outlook displays them identically.
Why strip EXIF metadata?
Every smartphone photo carries the full camera model, lens, exposure, the device's serial number, and — by default on iOS and Android — the GPS coordinates the photo was taken at. The recipient does not need any of that, and forwarding photos from a private location can leak it. The EXIF remover tool clears all of this in one click without touching the pixels.
When does zipping actually help?
For one or two attachments, zipping just adds friction — the recipient has to extract before viewing. For three or more, a ZIP keeps the email body tidy, lets the recipient preview inline (Gmail and Outlook both render ZIP contents), and avoids the dreaded 'forwarded with 12 attachments' wall of paperclip icons.
Steps
About 3 minResize to 1920 px
Open the resize tool and set the longest edge to 1920 px. Aspect ratio is preserved automatically.
Compress to JPG quality 78
Drag the resized files into the compressor and accept the default quality 78.
Strip EXIF metadata
Run the EXIF remover so GPS coordinates and camera serial numbers do not leave your machine.
ZIP three or more files
Right-click in your file manager and 'Compress to .zip' if you are sending more than two files.
Frequently asked questions
Can I send a 30 MB photo through Gmail?
Gmail caps attachments at 25 MB and routes anything larger through Google Drive, which requires the recipient to be signed into a Google account to view. Compressing first keeps the photo as a normal attachment that any recipient can open.
Will the recipient notice if I drop quality to 78?
Almost never. JPG quality 78 produces a file that is visually indistinguishable from the original at the displayed size on a phone or laptop, while saving 50–70% of the bytes. Side-by-side comparisons need a 200% zoom and a trained eye.
Is converting PNG to JPG safe for screenshots with text?
Yes if you save at quality 90 or above. Below that JPG starts smudging the edges of letters; at 90+ Outlook, Gmail, and Slack all display the screenshot identically to the PNG source while the file is 5–10× smaller.
Does this tool upload my photos to a server?
No. Every step — resize, compress, EXIF removal, ZIP — runs entirely in your browser using WebAssembly. The photos never leave your device.
What about HEIC photos from an iPhone?
Convert HEIC to JPG first using the dedicated HEIC tool, then run the compress flow. Outlook and Gmail still cannot render HEIC inline, so converting is required for the recipient to see the photo without downloading extra software.
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Shrink image files while preserving quality
Image Compressor