The two modes for JPG
Smaller files (lossy)
"Smaller files" re-encodes the JPG at the preset's quality. Balanced typically cuts a phone photo by 50–70 % with no visible change at normal sizes; Strong goes further and is visible when you zoom in.
Exact quality (lossless)
"Exact quality" leaves JPGs untouched, because JPEG can't be recompressed without loss. If you set a maximum width, the photo is resized and saved at maximum quality.
How to compress JPG files in ConvertX
- 1
Open Image Compressor
On the Home screen tap Image Compressor.
- 2
Select your JPG files
Tap "Select image files" and pick the JPG 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
- Start with Balanced and look at the estimate; move to Strong only if the number still isn't small enough.
- Resizing by maximum width (for example 2048 px) usually saves more than any quality setting, and nobody notices on a screen.
- Location and camera details are removed by default, which also saves a few kilobytes per file.
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
How much can I shrink a JPG?
50–70 % at Balanced for typical phone photos; more with a smaller maximum width. Already-compressed JPGs save less.
Does compressing a JPG reduce quality?
Yes, slightly, every time. Keep originals if you may compress again later.
Can I compress JPGs without any quality loss?
Not meaningfully; JPEG has no lossless recompression. Resize instead, or convert to a more efficient format like WebP or AVIF.
Is there a file count limit?
No. Everything runs on the device; batches of hundreds are fine.