Reduce a PNG below 5 MB without changing it to WebP
A checked PNG example: 5.77 MB to 4.96 MB, with the format preserved. See the settings, downloaded files and dimension changes.
By SheetSum · Example checked September 12, 2026
Compress a PNGChanging the file format is not always an option. An upload form may require PNG, or you may need transparency. In that situation, check both the output format and what changed to make the file smaller.
We tested one deliberately difficult synthetic PNG in SheetSum’s image compressor. It contains random RGB pixels, not a photograph. It is useful for checking behavior, but its compression ratio is not a prediction for your images.
The measured result
| Check | Original | Downloaded result |
|---|---|---|
| File size | 5,769,333 bytes (5.77 MB) | 4,964,079 bytes (4.96 MB) |
| Format | PNG | PNG |
| Dimensions | 1600 × 1200 | 1400 × 1050 |
Here, 1 MB means 1,000,000 bytes. The result is below 5,000,000 bytes. Original test PNG · Downloaded result.
The settings used
- Choose the PNG file.
- Select Fit an MB limit and leave the limit at 5.
- Keep the original output format.
- Run the compression and inspect the result before downloading.
The page reported Below size limit · dimensions reduced. We downloaded the file and independently opened it with an image decoder: it was a PNG measuring 1400 × 1050 pixels.
Open full-size result screenshot
PNG stayed PNG, but the pixels were resized
The file became about 14% smaller. The image dimensions also decreased. This was not a demonstration of lossless size reduction at the original resolution.
If your upload form requires both a maximum file size and minimum dimensions, check both rules. A file that meets the size limit may no longer meet the dimension requirement.
We also tested the default lossless PNG engine separately on the same input. That result was 5,763,023 bytes: only about 0.11% smaller and still over 5 MB. The two modes solve different problems. Standard compression can retain all pixels but may barely reduce an already difficult file; the target-size mode can reduce dimensions.
This sample has no transparent areas. Separate local-engine tests preserved transparency in a synthetic sample, but this target-size browser test does not establish transparent-image behavior for every file.
Before uploading your result
Open the downloaded file. Confirm its format, size and dimensions, then inspect small text and edges. Keep the original if the result is not suitable. A smaller file is useful only when it still meets your actual requirements.
Disclosure: SheetSum and this guide have the same operator. This synthetic example was checked on September 12, 2026 using the public English page and the downloaded file. Prepared with AI assistance. A 390-pixel viewport was checked; physical mobile devices and other image types were not tested in this example.