The two modes for PNG
Smaller files (lossy)
"Smaller files" re-encodes the PNG with the preset's quality. For photographic PNGs this is where the big savings are (often 70–90 %); for flat graphics the saving is smaller and the Light preset is enough.
Exact quality (lossless)
"Exact quality" re-encodes the PNG losslessly. Pixels are identical; savings are typically 10–30 % depending on the original encoder.
How to compress PNG files in ConvertX
- 1
Open Image Compressor
On the Home screen tap Image Compressor.
- 2
Select your PNG files
Tap "Select image files" and pick the PNG images. On desktop you can drag them in.
- 3
Pick a mode
Choose "Smaller files" (lossy, with the Light, Balanced, Strong or Maximum preset, or a custom quality) or "Exact quality" (lossless where the format allows).
- 4
Check the estimate
The app estimates the result size on one file before you run the batch, so you can adjust the preset first.
- 5
Optional: maximum width
Set a maximum width to resize large images; smaller images are left as they are.
- 6
Start and collect
Tap "Compress N images". The Queue runs the batch; the summary shows the total saved and View Library opens the results.
Tips
- Screenshots, logos and UI: use "Exact quality". Photos saved as PNG: use "Smaller files" or convert to JPG or WebP.
- Transparency is preserved in both modes.
- A maximum width cuts large screenshots from 4K monitors down to a shareable size.
Nothing is uploaded
Compression runs on the device; originals are never modified. Location and camera details are removed unless you turn on "Keep photo details". See the guide to compressing without losing quality for how the presets compare.
Frequently asked questions
Can I compress PNG without losing quality?
Yes. "Exact quality" is lossless recompression.
Why does my PNG barely shrink?
It was already well compressed. Converting to WebP (lossless) typically saves another 20–40 %.
Does compressing remove transparency?
No, both modes keep the alpha channel.