Why did my image get bigger after converting or editing?
You convert or edit an image to make it smaller, and the new file is bigger than the old one. It happens a lot, and your file is not broken. The format, the quality setting or a second save is usually the reason.
We ran every tool on this site on our test images: 576 of 3,110 files came out bigger than they went in. Below is where it happened, why, and how to get a smaller file.
What people run into
- On Stack Overflow someone saved a JPG photo as PNG and got a far bigger file. (user report, posted 2015-03-15) Same for us: all 25 photos grew as PNG, a median 483% of the JPG.
- A Stack Overflow question asks why a JPG came out bigger than the PNG it was made from. (user report, posted 2017-05-15) It happened to our flat images: as JPG at 92, 4 of 5 screenshots and 3 of 5 graphics grew.
- On Super User a full-page screenshot saved as JPEG was barely smaller than the PNG. (user report, posted 2026-09-18) Our screenshots as JPG at 92 were a median 122% of the PNG.
- On Graphic Design Stack Exchange someone saved JPGs again without changing anything, and the files grew. (user report, posted 2015-06-05) 5 of our 25 photos grew when saved again as JPG at 92.
- On the Adobe Community forum, JPGs saved from Photoshop came out far too large; a reply blames piled-up document metadata. (user report, posted 2019-07-25) Not in our tools: none of the 3,110 files they wrote carried EXIF data.
How to check it
- Compare sizes in bytes, not rounded KB. On Windows, right-click the file, choose Properties and read Size. On a Mac, select it and choose File, Get Info.
- When the result is not smaller, our tools say so. The compressor shows: “The result is not smaller than the original. Keeping the original may be better.” The converter shows: “The converted file is the same size or larger than the original.”
- Check what changed: the format (the file ending), the pixel size and the quality setting. Our tools show the format and pixel size under the original and under the result.
What we measured
We ran the compressor, converter, resizer, crop, rotate and watermark tools on 25 CC0 photos saved as JPG, and on 5 screenshots and 5 graphics saved as PNG, with every setting in our test plan. A file counts as bigger when it has more bytes than the file that went in.
Files that came out bigger, by tool
| Tool | Photos (JPG in) | Screenshots (PNG in) | Graphics (PNG in) |
|---|---|---|---|
| Compress | 49/987 | 60/220 | 68/220 |
| Convert | 83/525 | 18/105 | 18/105 |
| Resize | 4/223 | 15/34 | 14/26 |
| Crop | 8/100 | 6/20 | 14/20 |
| Rotate | 25/125 | 19/25 | 25/25 |
| Watermark | 50/250 | 50/50 | 50/50 |
Rotate, crop, resize and watermark save a JPG again at 92 and a PNG again as PNG. Every graphic grew when rotated or watermarked, so saving a PNG again is no way to shrink it; PNG compression is.
Source: our test on 2026-11-10 (harness eacd79c, site code eacd79c), headless Chromium 145 on a desktop Mac, 25 CC0 photos and 10 screenshots and graphics we made. How we test
The converter: which settings grew files
| Setting | Photos (JPG in) | Screenshots (PNG in) | Graphics (PNG in) |
|---|---|---|---|
| JPG 100 | 23/25, 197% | 5/5, 247% | 4/5, 278% |
| JPG 92 (default) | 5/25, 60% | 4/5, 122% | 3/5, 110% |
| JPG 80 | 2/25, 39% | 1/5, 97% | 1/5, 78% |
| WebP 100 | 25/25, 250% | 2/5, 78% | 4/5, 314% |
| WebP 92 | 3/25, 50% | 0/5, 49% | 0/5, 58% |
| PNG | 25/25, 483% | 5/5, 139% | 5/5, 186% |
Each cell: files that grew, then the median size as a share of the original. Chromium saves WebP at 100 without loss, which is why it is so large.
Source: our test on 2026-11-10 (harness eacd79c, site code eacd79c), headless Chromium 145 on a desktop Mac, 25 CC0 photos and 10 screenshots and graphics we made. How we test
The compressor: bigger only when the target was above the file's size
| Input | Runs with a KB target | Target at or above the file's size | Came out bigger | Of those, the first save at 92 |
|---|---|---|---|---|
| Photos (JPG) | 987 | 105 | 49 | 37 |
| Screenshots (PNG) | 210 | 108 | 60 | 58 |
| Graphics (PNG) | 210 | 156 | 68 | 64 |
With a target below the file's own size, none of the 1,038 runs came out bigger.
Source: our test on 2026-11-10 (harness eacd79c, site code eacd79c), headless Chromium 145 on a desktop Mac, 25 CC0 photos and 10 screenshots and graphics we made. How we test
Why it happens, and the fix for each
The format changed
JPG is made for photos. PNG keeps every pixel and suits screenshots, logos and drawings. Every one of our photos grew as PNG, a median 483% of the JPG. Going the other way, PNG to JPG at 92, 4 of 5 screenshots and 3 of 5 graphics grew.
HEIC and WebP store photos more tightly than JPG, so a JPG copy is bigger. At 92 our JPGs were 2.3× to 3.5× the size of the HEIC (HEIC to JPG) and 1.6× to 3.4× the size of the WebP (WebP to JPG). WebP to PNG gave 9.7× to 25.9× the size of the WebP.
Fix: keep photos as JPG and screenshots or graphics as PNG. If a form needs another format, convert, then check the size.
The quality setting was high
Quality 100 does not mean the original's quality; it means less compression. At JPG 100, 23 of 25 photos grew, a median 197% of the original. At 92, 5 grew, and at 80, 2. WebP at 100 grew every photo, because Chromium saves it without loss.
Fix: start at 92, the converter's default, and go down to 80 if the file must be smaller.
The JPG was already saved tightly
Every save starts again from the pixels, not from the old file. A JPG that was saved at a low setting can grow when it is saved again at 92. 5 of our 25 photos did this. As JPG at 92 they came out 102% to 138% of their size. Rotate, crop, resize, watermark and the compressor grew the same photos and no others. 4 of them are night shots.
Fix: if you only need the same picture, keep the original. To shrink it, use the compressor with a target below its size, or the converter at a lower setting.
The compressor's target was above the file's size
The compressor first saves the image at 92. If that file already fits the target, it hands it back, even when it is bigger than the original. That first save gave 159 of the 177 bigger files in the table above; in the rest, the search picked the best quality under a target that was itself above the file's size. The compressor never goes above 92 and never adds pixels.
Fix: type a target below the file's current size. If the file already fits the limit, upload the original.
Metadata
Some apps store extra data in the file: camera details, edit history, a preview. The Adobe forum report above is one case. Our tools do not copy it: 23 of our 25 photos carried EXIF camera data, and none of the 3,110 files our tools wrote did. Metadata is not why a file from this site grew.
Fix: in another editor, export without metadata.
What to do
- Compare the new file with the original in bytes. If the original already fits, upload the original.
- Pick the format by content: photos as JPG, screenshots and graphics as PNG.
- Use quality 92 or lower, not 100.
- For a KB limit, use the compressor with a target below the file's size.
- For a PNG, try PNG compression, which keeps every pixel.
What our test covers
All numbers come from one run of our benchmark harness, which runs this site's own code in a browser on a desktop Mac. The HEIC and WebP numbers are from the tests on their own pages, linked above. Our one orientation test file is left out of the counts.
We compared bytes, not how the pictures look. See how we test.
Sources
Official pages say what the company states. User reports are what people describe on forums; they are not rules, and we use no number from them.
User reports
- Stack Overflow: Why does PNGing an image from a JPG make it so much bigger?, posted 2015-03-15
- Stack Overflow: My .jpg file is larger than .png?, posted 2017-05-15
- Super User: Why does saving a full page screenshot as JPEG barely shrink the file compared to PNG?, posted 2026-09-18
- Graphic Design Stack Exchange: When resaving JPEGs, the file size increases, but the quality is not changed. Why?, posted 2015-06-05
- Adobe Community: Jpegs saving too large, posted 2019-07-25
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