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Image DPI changer.

Change print density, keep every pixel. Inspect and update JPEG or PNG resolution metadata without resizing or re-encoding your image.

Files stay on your device

1. Choose an image

Inspect the resolution stored in your file.

Or drop one image here. Your file stays on this device.

2. Set target DPI

Change print density, keep every pixel.

Choose a positive whole-number DPI. The same value is used horizontally and vertically.

Estimated print size

Choose an image to calculate its print size.

Uses target density and the image’s orientation. Your printing app may override this size.

Metadata only. No extra detail.

Pixels are not resized or re-encoded. Changing DPI does not sharpen an image or improve print quality.

3. Apply and download

Choose a JPEG or PNG to begin.

How to change image DPI

  1. Choose your image.Select a local JPEG or PNG. Check its pixels and stored density; missing DPI is shown as unknown.
  2. Set the target DPI.Enter a value or use a preset. See the corresponding print size in inches and centimetres.
  3. Apply and download.The tool edits density metadata, reads it back from the exported bytes and prepares your download.

DPI changes print size, not detail

A 2400 × 1600 pixel image at 300 DPI suggests an 8 × 5.33 inch print. A higher DPI suggests a smaller print with the same pixels. It adds no sharpness or detail. Printing software can override this setting.

Original encoded pixels

JPEG scan data and PNG image chunks are copied without re-encoding. Color profiles, transparency, animation data and orientation are preserved. A browser-rendered still thumbnail is for preview only; it is not the exported image.

Local processing

File reading and editing happen in your browser. Images and names are not uploaded, logged or stored by this tool. Download saves only when you click it. Cancel, reset or a new selection stops processing and releases the result.

Frequently asked questions

What does this tool actually change?

For JPEG, it writes JFIF horizontal and vertical density in dots per inch and updates the primary EXIF XResolution, YResolution and ResolutionUnit when EXIF exists. If JFIF is absent, it adds it. For PNG, it writes the pHYs chunk in pixels per metre and updates primary eXIf resolution when present. The same target is used for both axes, so a non-square pixel aspect ratio becomes square.

Other metadata is kept, including location or camera information if present. This is not a metadata-removal tool. XMP, IPTC, text metadata, embedded thumbnail and auxiliary-image density are not inspected or updated; an application that prefers those fields can display a different value.

Why does a PNG show slightly different DPI?

PNG stores whole pixels per metre, so the exact value requested may need rounding. For example, 300 DPI becomes 11,811 pixels per metre, which is 299.9994 DPI. The output readout and target print-size calculation use the actual stored value. Existing EXIF can still store exactly 300 DPI.

Does 300 DPI make a low-resolution image better?

No. Presets are convenient density values, not quality settings or printing recommendations. The pixel grid is unchanged. If you need different pixel dimensions, use the image resize tool. If a file is already set to the requested fields, the result says when the output bytes are unchanged.

Which files and browsers work?

JPEG and PNG are identified from their contents, regardless of filename. Animated PNG keeps its frame data; only the canvas density is edited. A JPEG with extra images retains them and changes the primary image only. Formats such as WebP, GIF and TIFF are not edited here.

There is no tool-imposed file-size or pixel cap. Available memory and valid format fields determine what works. JFIF density is a 16-bit integer; PNG density is a 32-bit integer in pixels per metre. A full JPEG EXIF segment may have no room for new fields. A missing preview decoder does not prevent a metadata-only download; such a download preserves the source pixels without validating or repairing their compressed data.