One photo, every size
An 11-megapixel harbour photo from a Sony DSLR (4.97 MB, 3719 × 3056; public domain, Wikimedia Commons) at each preset:
| Limit | File | Pixels | Score |
|---|---|---|---|
| 20 KB | 19.9 KB | 794 × 652 | 63 |
| 50 KB | 49.3 KB | 1555 × 1278 | 61 |
| 100 KB | 99.3 KB | 2434 × 2000 | 64 |
| 200 KB | 198 KB | 3719 × 3056 (full size) | 64 |
| 500 KB | 487 KB | 3719 × 3056 (full size) | 78 |
| 1 MB | 666 KB | 3719 × 3056 (full size) | 81 |
| 2 MB | 666 KB | 3719 × 3056 (full size) | 81 |
From 1 MB up the photo already looks the same as the original (score 80 or more) at 666 KB, so PicoDiet stops there instead of filling the limit.
Choosing a size
| Size | Typical use |
|---|---|
| 20 KB | Exam and application form photos; signatures (try 10 KB) |
| 50 KB | ID and profile photos on portals |
| 100 KB | Job sites, email, product thumbnails |
| 200 KB | Full-screen photos on blogs, listings, ads |
| 500 KB | Near full size, for portals that keep originals |
| 1 MB | Full size; forum and older site limits |
| 2 MB | Sites and forms with a 2 MB upload limit |
Any other number works too: choose Custom and type it in KB, or in MB such as 1.5 MB.
KB, kB and KiB
A form that says 100 KB may mean 100,000 bytes or 102,400 (Windows counts 1024 bytes to the kilobyte). PicoDiet aims under the smaller one, 100,000 bytes, so the file passes either way. Windows then shows it as about 97 KB.
How PicoDiet gets an image under the size you choose
It looks for the best-looking file that fits, and scores every try against your original.
- Small enough already? If the image fits at quality score 80, which looks the same as the original, PicoDiet stops there instead of filling the limit.
- Lower quality first. Otherwise it lowers the quality until the file fits.
- Fewer pixels last. If that would take the score under 60, where flaws start to show, it reduces the dimensions instead and keeps the largest size that still scores 60. A smaller sharp photo looks better than a big blotchy one.
Photos come out as JPEG, which most upload forms accept. Images with transparency stay PNG and animated GIFs stay GIF. You can choose another format under Options.
What happens to your images
Uploaded over HTTPS to the nearest of our servers, processed automatically, and deleted within 3 minutes after you finish. Never shared, sold or used for training. No account needed. Privacy policy
Questions about reducing size in KB
How do I reduce a photo to exactly the KB a form asks for?
Pick that size above the results, or type it under Custom. The file comes out a little under it, usually within 3%, which is what a form's "less than" means.
Why did my photo get fewer pixels?
At small sizes a full-size photo would look blotchy, so PicoDiet makes it smaller and keeps the largest size that still looks clean. At 20 KB a 12-megapixel photo ends up about 580 to 800 pixels on the long side.
Can I make an image bigger in KB?
No. PicoDiet only makes files smaller, and choosing a higher limit won't enlarge one. If a form asks for at least a certain size and your original is below it, you need a larger original.
Does it change my photo's colours or orientation?
No. The colour profile is kept and photos come out upright, as your phone shows them. Camera and location data (EXIF and GPS) are removed.
Are my images private?
Yes. Images are uploaded over an encrypted connection to the nearest of our servers, optimized, and deleted within 3 minutes after you finish. They are never shared, sold or used for training, and there is no account to sign up for. Details are in the privacy policy.