Short answer
Start with one difficult sample image. Choose the output format and the image changes you need, then run the compatibility check.
Save the test result in a separate folder and inspect it. Reuse the profile for the full batch only after the sample looks right.
What batch conversion does
A batch applies one tested set of settings to many eligible files. Just Converter can expose resize, fit, fill, stretch, canvas, rotation, background, alpha, metadata and target-size controls when they apply. Crop and watermark are not part of this image workflow. Each source format uses its own decoder. Preflight lists every accepted file and identifies each file that lacks compatible support.
Before you start
- Copy a representative file that includes transparency, small text or other difficult detail.
- Confirm the destination format, dimensions, size limit and metadata policy.
- Use separate source and output folders.
- Choose rename, overwrite or skip behavior before duplicate names occur.
Build the batch
Prove one result
Add the sample, choose the output and only the operations needed for the destination.
Read preflight
Review supported inputs, the preflight output list, name collisions, warnings and optional components.
Inspect the sample
Check dimensions, orientation, sharp detail, color, transparency, metadata and measured bytes.
Add the batch
Save the approved profile, add files or a folder and review the final plan before processing.
Review the completed set
- Compare the input count with success, failure and skipped counts.
- Open examples from different source formats, not only the first output.
- Check that filenames and folders follow the selected collision rule.
- Keep sources until the destination accepts the results.
Recovery and limits
Use the saved batch results to resume unfinished work, retry failed files, or start over. A target file size is not guaranteed; the app reports when the requested size cannot be reached within its allowed settings.
You can add up to 1,000 files directly or discover up to 10,000 files in a folder. Each image can be up to 50 MiB. HEIC, HEIF, RAW, and SVG files work only when the compatibility check finds a suitable decoder on the PC.
Just Converter
Preflight a local image job, save proven settings and keep individual failures visible.