See the DPI saved in JPG and PNG files and change it to 300, 600 or any value without re-saving the picture: only the resolution fields in the file header change, so quality and pixels stay identical. Works on batches.
Works in your browser. What you paste or upload is processed on your device.
Choose one or more JPG or PNG files. The current DPI and pixel size of each appear in the list.
Tap 300 DPI for print, or enter any value. The print size at that DPI updates for every file.
Press Change DPI. Only the resolution fields in each file's header are rewritten.
Download each file, or all of them as a ZIP. File names stay the same.
DPI (dots per inch) is a number stored inside an image file that tells printers and apps how large to print it. It doesn't change the pixels: a 2400 × 3000 pixel photo is the same picture at 72 or 300 DPI, it just prints at 33 × 42 inches or 8 × 10 inches. Print shops, publishers and some application forms still ask for files marked 300 DPI, and many phones and editors save 72 or 96 DPI or leave it blank.
This tool reads the DPI already saved in each JPG or PNG, shows the pixel size and the print size it gives, and rewrites only the resolution fields: the JFIF header and EXIF resolution in JPGs (and the Photoshop resolution block when present), and the pHYs chunk in PNGs. The compressed image data is copied byte for byte, so there is no re-compression and no quality loss. You can process up to 50 files in one run.
Honest limits: changing DPI doesn't add detail. If a print shop needs 300 DPI at 10 × 15 cm, the image needs about 1181 × 1772 pixels; marking a small image as 300 DPI only makes it print smaller. To change the pixel count, use the Image Resizer. This tool handles JPG and PNG only; WebP, HEIC and other formats need converting first.
Re-saving a photo in an editor just to change the DPI re-compresses it and loses quality, and online converters often upload your files. Rewriting the header in your browser takes a second per file, leaves the picture untouched and keeps your images on your device.
Something else? Ask the team
Not with this tool. It rewrites only the resolution numbers in the file header and copies the compressed image data unchanged, so the pixels are identical to the original. File size changes by at most a few bytes.
Add the image, choose 300 DPI and press Change DPI. The downloaded file reports 300 DPI in Windows file properties, macOS Preview, Photoshop and print software. The pixel count stays the same, so check the print size shown next to each file.
Add it to this tool: the list shows the DPI saved in the file and where it came from (JFIF, EXIF, PNG pHYs or Photoshop). Checking is free; a run is used only when you press Change DPI. If the file has no DPI, most apps assume 72 or 96.
No. DPI only sets how big the image prints. The same pixels printed at 300 DPI come out smaller and look sharper on paper, but no detail is added. For a larger print at 300 DPI you need more pixels from the original camera or scan.
JPG (JPEG, JFIF) and PNG. Other formats need converting first, and converting re-encodes the picture, so convert to PNG for no further quality loss and then set the DPI here.
Yes. Add up to 50 files and they all get the same DPI in one run. Download them one by one or together as a ZIP.
No. The files are read and rewritten in your browser on your own device. Our server only counts runs so it can apply the daily free run.
You get one free run per tool per day, and one run covers every file in the batch. After that, each run costs 5 credits with a free AI Rank Lab account. Checking the current DPI is always free.
Each one opens on its own page and works straight away, with no sign-up.
Crop photos to any size or aspect ratio
Crop a photo into a round, transparent PNG
Rotate or straighten images, one or many
Mirror images horizontally or vertically
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