How much it saves
Halving the width quarters the pixel count. A 4000×3000 photo capped at 2000 px wide has a quarter of the pixels and, at the same quality, roughly a quarter of the file size, before any compression preset is applied. That is why the compression guide says to resize first.
How to resize a batch in ConvertX
- 1
Open Image Compressor
On the Home screen tap Image Compressor. Resizing lives in the compressor because it's the biggest size lever.
- 2
Select the images
Tap "Select image files" and pick the photos; on desktop, drag them in.
- 3
Set the maximum width
Turn on "Maximum width" and enter the value, for example 2048. Images wider than that are scaled down proportionally; narrower ones are left as they are.
- 4
Choose a mode
"Exact quality" resizes with no additional compression loss (JPG is re-saved at maximum quality). "Smaller files" resizes and compresses with the preset.
- 5
Check the estimate and run
The estimate shows the resized result for one file. Tap "Compress N images"; results go to the Library.
Formats
Works on every input the app reads (JPG, PNG, WebP, BMP, TIFF, GIF; HEIC on Android 9+). Output follows the compressor's rules: HEIC becomes JPG, BMP and TIFF become PNG in "Smaller files" mode, GIFs stay animated.
Frequently asked questions
Can I set an exact width and height?
No. ConvertX resizes by maximum width only and keeps the aspect ratio. There is no cropping, no exact-size output and no upscaling.
Will small images be enlarged?
No. Only images wider than the maximum are changed.
Does resizing lose quality?
Downscaling discards pixels by definition, but at screen sizes the result looks identical. In "Exact quality" mode no extra compression is applied.
Which width should I use?
2048 px for anything viewed on a screen, 1600 px for messaging, 1200 px for web thumbnails and listings.