Troubleshooting
“No supported images found”
The app only processes JPG, PNG, WebP, and TIFF files.
If your folder contains HEIC, GIF, BMP, RAW, or other formats, they will not be counted. Convert them first before running compression.
The Compress button stays disabled
The button is disabled until:
- An input folder is selected
- The selected folder contains at least one supported image
- A batch is not already running
If the image count is 0, the app found no supported files in that folder.
Some files were skipped
This usually happens when Skip already compressed files is turned on and a file with the same output name already exists in the output folder.
Turn the switch off if you want to overwrite or regenerate those outputs.
The preview does not match the final file exactly
The preview is a reduced-resolution proof designed to help you judge settings quickly. It is not intended to be a byte-for-byte copy of the final exported image.
Use it to evaluate quality direction, visible artifacts, and format behavior before the full run.
The Preview estimate is also only an estimate based on the currently selected sample file. The final batch summary may show a different total reduction across the whole folder.
Output images are still too large
Try one or more of these:
- Lower the quality value for JPG or WebP output
- Convert photographic images to WebP instead of PNG
- Use JPG instead of Same as Input if the source folder contains many PNG or TIFF files
- Turn on Strip EXIF metadata if embedded metadata is unnecessary
- Check the preview estimate before running and compare it with the final batch summary afterward
Output images look blurry or blocky
That usually means compression is too aggressive for the content.
- Raise the quality value
- Try PNG for screenshots, text, graphics, or logos
- Compare Original and Split preview modes before running the full batch
The app reports errors for some files
Open the Activity Logs panel to see the filename and error.
The log also shows per-file successes, skipped files, and the final batch summary, which makes it easier to spot whether the problem affected one file or the whole run.
Common causes:
| Error type | Likely cause |
|---|---|
| Unsupported image data | File extension looks valid but the file is corrupt or not really an image |
| Read error | Source file was moved, locked, or deleted during processing |
| Write error | Output folder is unavailable, read-only, or blocked by permissions |
Output folder will not open
The Open Output Folder button uses Windows Explorer. If Explorer does not open, navigate manually to the output subfolder inside your selected input folder.
Still stuck?
Use the app’s Feedback & support menu to email hello@3thousand30.com, or open an issue on GitHub.