How to bulk change DPI
- Select all the files in your folder and drop them on the box, or use Choose images and select several files at once.
- Pick 300, or any other value. The value applies to every file in the list.
- Check the print size in each row. Rows with a small print size tell you which files have too few pixels.
- Press Download all as zip. Each file in the zip is named with the new value, for example poster-300dpi.png.
Why this is fast
The tool does not re-save your pictures. For each file it changes only a few bytes in the header, so a big batch finishes quickly. Your computer does the work, so there is no upload queue and no limit on how many files you can process in a day.
The files are held in memory while you work. The limit is 500 MB for the whole batch. For bigger jobs, run two batches.
What happens to file names
Names stay readable. The tool adds the DPI to the end of the name and keeps the extension. If two files end up with the same name, the second one gets -2 so the zip never overwrites a file.
Mixed files in one batch
JPEG, PNG and WebP can go in the same batch. WebP files are saved as PNG, because PNG can store a DPI value. The row tells you when this happens. Files in other formats show a clear message and are skipped, and the rest of the batch continues.
Questions
- How many images can I change at once?
- There is no fixed file count. The files together can be up to 500 MB, because they are held in your browser memory while you work.
- Can I give each image a different DPI?
- Not in one batch. Every file in the list gets the value you pick. Run the files that need another value in a second batch.
- Does the zip change the quality?
- No. The zip stores the files as they are, without extra compression, so the pictures inside are exactly what you would get from single downloads.