Short answer
Write down the website's file-size limit. Convert a copy of the image toward a slightly smaller size, then open the result and make sure it still looks good.
When to use this method
A target-size job is useful for portals and upload limits. Format, dimensions and visual quality still trade against file size.
Target-size behaviorWhat happens when the requested size can or cannot be reached.
- How it works
- The app uses built-in search bounds and deletes the partial output when the requested target cannot be reached.
- Important limit
- A limit below the practical minimum for that format is unreachable without changing dimensions, quality or format. The app reports an unreachable-target error instead of keeping an above-limit partial result.
What you need before changing the image
- The original image and a copy to test.
- The exact maximum size shown by the website or app that will receive the image.
- A format the destination accepts, such as JPG, PNG or WebP.
Work toward a real byte limit
Record the destination limit
Choose a target a little below the maximum.
You should see: the target size in the job settings.
Choose a suitable format
Use JPG for many photos and PNG or another compatible format when sharp edges or transparency matter.
You should see: the selected extension in the planned output name.
Let the app test file-size settings
Enter the target size and let the app try the allowed output settings.
You should see: either a completed file or a clear message that the target cannot be reached.
Inspect the reported result
Open a completed file at normal viewing size.
You should see: a readable picture whose measured size is below the real limit.
If the image stays above the limit
Confirm the measured output in bytes, not the quality slider. Try a smaller pixel size or a format suited to the picture, then inspect text, faces, edges, and transparency. The app reports when it cannot reach the requested limit with the allowed settings. It does not silently keep an unreadable result.
Target-size mistakes
- Treating the requested size as a guarantee
- Ignoring dimensions while chasing bytes
- Replacing the only source copy
Image checkpoint
- The reported size is within the destination's actual byte limit, including any safety margin.
- An unreachable target produces an error and no partial output.
- At normal viewing size, the dimensions, text, faces, edges, gradients and transparency remain suitable for their intended use.
Just Converter
Try the allowed image settings to approach a requested byte limit and report clearly when the goal cannot be reached.