How to send photos that are “too big” — without wrecking them

A photo from a modern phone is typically 3–8 MB. Gmail caps a whole message at 25 MB, Outlook at 20 MB, and plenty of government and job-application forms reject anything over 2 MB per file. So “attachment too large” isn’t bad luck — it’s the default outcome of sending camera photos anywhere.

The good news: for viewing on a screen, most of those megabytes are wasted, and you can remove them without anyone noticing.

Where the megabytes actually live

Two things drive a photo’s file size:

• Resolution — the number of pixels. A 12-megapixel photo is 4000 × 3000 pixels. A laptop screen is around 2 million pixels; a phone screen even less. Most of the detail in a full-resolution photo physically cannot be displayed on the recipient’s screen.
• Compression quality — how aggressively the JPEG encoder discards detail. Cameras save at very high quality settings to leave room for editing, which is more than you need for sharing.

Both are multiplicative, which is why the fix works so well: halving the longest edge cuts roughly 75% of the data, and dropping JPEG quality from ~95 to ~75 removes another large slice that the eye can barely detect on a screen.

What to actually do

1. Resize to what the recipient needs. For email, chat and web forms, 1600 px on the longest edge is plenty; even 1280 px looks sharp on most screens. Use a resize tool and set the longest edge — the aspect ratio takes care of itself.
2. Compress with a sensible quality. Around 70–80% JPEG quality is visually indistinguishable from the original at screen sizes. A compressor with a live size estimate lets you watch the megabytes fall as you adjust — no guessing.
3. Have a hard limit? Set a target size. If a form says “max 2 MB”, don’t iterate by trial and error — use a target-size setting and let the tool find the quality level that hits it.
4. Sending many photos? Bundle them into a single compressed PDF. One file attaches faster, arrives in order, and the per-image compression keeps the whole document under email limits.

What not to do

• Don’t screenshot the photo. It re-samples the image to your screen resolution in an uncontrolled way, often increases the size for PNG screenshots, and strips nothing you couldn’t remove properly.
• Don’t zip photos. JPEGs are already compressed; zipping them saves single-digit percentages and makes them harder to open on phones.
• Don’t re-save repeatedly. Every JPEG re-save at a new quality loses a little more detail. Compress once, from the original, at the size you need.

Print is the exception

Everything above is for screens. If the recipient will print the photo, resolution matters again: printing wants around 300 pixels per inch, so a 4×6” print needs about 1800 × 1200 px, and an A4 print closer to 3500 px on the long edge. For print, keep the resolution and lower the quality only slightly (90%+).

The privacy angle

Most online compressors upload your photos to their servers to do this work. That’s an unnecessary trade: browsers can decode, resize and re-encode images locally. The tools linked in this guide run entirely on your device — the photo you’re shrinking never travels anywhere until you attach it to the email.