How to Reduce a Photo's File Size (MB to KB)

A photo straight from a modern phone is often several megabytes. That's more than many job portals, government forms and websites accept, and it makes emails with several photos slow to send. You can usually bring a photo down to a few hundred KB, or even under 100 KB, without it looking noticeably worse on screen.

What makes a photo file big

Two things decide a photo's file size:

1. Its dimensions in pixels. A 12-megapixel photo is 4,032 × 3,024 pixels, far more than a screen or a form needs. Halving both dimensions leaves a quarter of the pixels.
2. Its compression quality. JPEG throws away detail your eye is unlikely to notice. Lower quality settings mean smaller files, until blockiness starts to show.

Reducing both gives the biggest savings with the least visible loss.

The quick way: compress to an exact size

1. Open the Image Compressor.
2. Choose your photo (or several at once).
3. Enter the target size you need, such as 500 KB, 200 KB or 100 KB.
4. Download the result. The tool finds the best quality that fits under your target.

Everything happens in your browser; your photos aren't uploaded anywhere.

For very small targets, resize first

Getting a detailed photo under 100 KB or 50 KB is easier if you shrink its dimensions first. Use the Image Resizer before compressing. As rough starting points:

Results vary with the photo: a portrait against a plain wall compresses much further than a busy landscape full of leaves.

Using what's already on your device

• iPhone: when you attach large photos in the Mail app, it often lets you choose Small, Medium, Large or Actual Size before sending.
• Windows: in the Photos app, open the picture, open the three-dot menu and choose Resize image.
• Mac: in Preview, choose Tools → Adjust Size to change dimensions, then File → Export and drag the Quality slider to shrink it further.

Pick the right format

• JPG is best for photos.
• PNG is best for screenshots, logos and graphics with sharp edges or transparency, but it's large for photos. Converting a photo from PNG to JPG often cuts its size dramatically; use PNG to JPG.
• WebP is smaller than JPG at similar quality and supports transparency, but some older forms don't accept it.

Tips for the best result

• Start from the original. Each time a JPG is saved again, it loses a little more detail.
• Keep the original somewhere safe; the small copy is for sending.
• Crop first. Removing background you don't need shrinks the file for free. Use the Image Cropper.
• Check the form's other rules. Many upload forms also require specific dimensions or a specific format, not just a maximum file size.