Key takeaways
- Two settings control size: the quality slider (10 to 95 percent) and the largest side in pixels.
- Lower the largest side first for big camera photos, then adjust quality in small steps.
- You cannot enter an exact file size, so try a setting, check the size and adjust.
- If a photo is already small, the tool returns the original and tells you.
Why photos are so large
Phone cameras take pictures with many millions of pixels, far more than a form, an email or a screen needs. A single photo can be several megabytes. Many upload forms ask for small files, so you need to bring the size down without making the photo unreadable.
Two settings, and what each one does
| Setting | What it changes | Effect on size |
|---|---|---|
| Largest side (pixels) | Reduces the width and height of the picture | Large. Often the biggest saving |
| Quality (10 to 95%) | Reduces how much detail is kept | Medium. Lower numbers give smaller files and softer detail |
Reducing the largest side removes pixels you would never see on a screen. Lowering quality then trims what is left.
Step by step: get under a limit
- Check the limit on the form and the current size of your photo.
- Open Compress Image and add the photo.
- Set the largest side. For a form photo, a value such as 1200 or 1600 pixels is often plenty. Keep a larger value if the photo must stay detailed.
- Set the quality. Start around 80 percent.
- Download the result and check its size. If it is still too big, lower the largest side or the quality a little and try again from the original.
If the form needs exact dimensions
Some forms ask for a photo of a particular width and height. Use Resize Photo to set exact pixel dimensions, and Crop Image first if you need to cut the picture to the right shape. Then run it through Compress Image if the file is still too large.
When the photo will not get smaller
If a photo is already small or well compressed, compressing it again may not save anything. In that case, the tool returns your original file and says so. Try a smaller largest side instead.
Pick the right file type
JPG is usually the lightest choice for photos. PNG files are often much larger for photographs, so convert them with PNG to JPG if size matters. If you are preparing images for a website, Image to WebP can make them lighter still. Read more in JPG vs PNG.
Frequently asked questions
Can I choose an exact file size such as 100 KB?
No. You set the quality and the largest side, then check the result. Try a setting, look at the size and adjust.
What quality setting should I use?
Around 70 to 80 percent is a good starting point.
What does the largest side option do?
It limits the longest edge of the image in pixels, which makes large photos smaller as well as lighter.
Why was my image not made smaller?
If an image is already small, compressing it again may not help. You get the original back with a note.
Are my photos uploaded?
No. Compression runs in your browser and the photo stays on your device.