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How to reduce a photo's file size for an online form or an email

3 min readRelated tool: Compress Images Online

"The file exceeds the maximum allowed size (2 MB)." It's one of the most frustrating messages on any form: a job application, a government portal, your insurer's website or your company's expense tool. The photo looks fine, but it's too heavy. The good news is that it can almost always be cut to a tenth of its size with no visible difference.

Why photos are so heavy

A modern phone photo has 12 to 50 megapixels. That's an image 4000 to 8000 pixels wide, meant for cropping or printing large. To view it on a screen or to let someone read a document, most of that information is unnecessary.

An image's file size mostly depends on two things:

  1. Its dimensions in pixels. Halving the width divides the number of pixels by four.
  2. The compression quality. JPG and WebP discard detail the eye barely notices; the lower the quality, the more they discard.

The first is the most effective and the least noticeable.

The quick recipe

Open the image compressor, add your photo (or several at once) and use these values:

What it's for Format Quality Max width
Form with a 1–2 MB limit JPG 75% 1920 px
Profile photo or résumé JPG 80% 1280 px
Image for a website WebP 75% 1920 px
Scanned document JPG 70% 1920 px

With these settings, a 4 MB phone photo usually ends up between 200 and 500 kB. The tool shows each image's size before and after plus the total savings, so you can adjust and repeat if needed.

JPG or WebP?

WebP is around 25–35% smaller at the same quality, and every current browser displays it. But many forms only accept "JPG, JPEG or PNG", and some desktop programs still can't open it. Rule of thumb: JPG for forms and email; WebP for publishing on your own website.

If your image is already WebP and the form won't take it, convert it to JPG with the image converter.

What if it's a PNG?

Screenshots are usually saved as PNG, a lossless format that's heavy for photos but ideal for text and interfaces. If it's a screenshot with text and you need it smaller, convert it to JPG at high quality (85–90%) or reduce its dimensions with the image resizer. If it's a photo accidentally saved as PNG, converting it to JPG can cut its size by 80% or more.

Common limits worth knowing

  • Gmail accepts attachments up to 25 MB per message; above that it offers to share via Google Drive.
  • Outlook usually limits attachments to 20 MB.
  • Web forms and government portals: limits vary a lot, but 1, 2 and 5 MB per file are common. The limit is usually shown next to the upload button.

Keep in mind that email attachments grow by about 33% because of the Base64 encoding email uses, so a 19 MB attachment may not fit in a 25 MB limit.

What not to do

  • Dropping quality to 30% "just to be safe". Blocks and halos appear and document text becomes hard to read. Reduce the width first.
  • Taking a screenshot of the photo. It works, but you lose resolution unpredictably and often end up with a PNG that's even heavier.
  • Compressing the same image several times. Every JPG pass loses quality. Always compress from the original.

Frequently asked questions

How do I get a photo under 1 MB?

With a max width of 1920 px and 75% JPG quality, almost any photo ends up under 1 MB. If it still doesn't fit, lower the width to 1280 px before lowering the quality further.

Does compressing reduce quality?

Technically yes, because JPG and WebP discard information. In practice, between 70% and 85% the difference isn't visible at normal size. Going below 60% is what you'll notice.

Are my photos uploaded to a server?

No. Toolbrik's compressor runs inside your browser, so the photos never leave your computer or phone. That matters when they're personal documents.

Why is an image bigger after compressing?

It happens when the original was already highly optimized or is a simple graphic with few colors. In that case, keep the original.