Drop a PNG or JPEG here
or click to choose · or paste (Ctrl/Cmd + V)
processed in your browser · never uploaded
Drop or click to replace
Change a PNG or JPEG's DPI (dots per inch — its print resolution). The same pixel image prints at a different physical size depending on its DPI: a 3000×2000px photo prints at 10×6.67 inches at 300 DPI, but 41.7×27.8 inches at 72 DPI. Use it when a print shop asks for "350 DPI," when an image lands huge or tiny after pasting into Word or InDesign, or when you need a photo to print at an exact size. This tool never resamples (scales) the pixels. It only rewrites the resolution metadata — the pHYs chunk in PNG, the JFIF density fields in JPEG — so the image data stays bit-for-bit identical and the operation is completely lossless. There are two ways to work: in "DPI" mode, choose a 72 / 96 / 150 / 300 / 350 / 600 preset or type any value; in "print size" mode, type the final printed width or height (mm / cm / inch) and the tool computes the DPI that produces it. It also shows the loaded image's current DPI and pixel dimensions. Your image is never uploaded, stored, or sent anywhere — every step runs locally on your device. Supported formats are PNG and JPEG.
How to use
- Drop a PNG or JPEG in, click to choose, or paste it. Its current DPI and pixel size are shown.
- Use "DPI" to pick a preset or type a value, or "print size" to type the final printed width/height (mm/cm/inch).
- Check the result panel for the resulting DPI and the printed physical size.
- Click Download image. The pixels are unchanged (lossless) and the image is never sent anywhere.
FAQ
Does changing DPI reduce quality?
No. The tool never resamples (scales) the pixels — it only rewrites the resolution metadata (pHYs in PNG, JFIF in JPEG). The image data stays bit-for-bit identical, so it is completely lossless.
Will raising the DPI make the image sharper?
No. DPI only decides how many inches the same pixels print across. Setting 300 DPI makes the print smaller and packs more pixels per inch, but it does not add pixels. To gain real detail you need to resize/upscale instead.
Is my image uploaded to a server?
No. All processing happens in your browser. Your image is never uploaded, stored, or sent anywhere — it is handled entirely on your device.
Can I set the DPI from a target print size?
Yes. In "print size" mode, type the final printed width or height in mm, cm, or inches and the tool back-calculates the DPI that yields that physical size. It also shows the size of the other side at the same time.
Which formats are supported?
PNG and JPEG. DPI is written to the PNG pHYs chunk or the JPEG JFIF density fields. A JPEG without a JFIF segment gets a standard JFIF added (the EXIF resolution tags are left unchanged).
Why does it say the current DPI is "none"?
Images without resolution metadata (many web images and some screenshots) show this. You can still pick a target DPI and write it in to lock the physical print size.