ImgBox

Change Image DPI

Change the print resolution (DPI) of an image entirely in your browser. For PNG files, the standard pHYs chunk is written; for JPEG the JFIF APP0 density fields are updated — both fully spec-compliant. Choose from 72 / 150 / 300 DPI presets or enter a custom value. The real-time physical size display (cm or inch) shows exactly how the image will print. Optionally resample pixels to hit a specific physical size. Every step happens locally — your files never leave your device.

Related Tools

⇲Resize Image◐Compress Image⇄Convert Image Format

How to use

Purpose

Change image DPI (Dots Per Inch) metadata — typical use is shifting from screen 72/96 DPI to print-ready 300 DPI. Important: this only changes the metadata tag, not the actual pixel count. True print sharpness depends on pixel dimensions, so for high-quality print you should first upscale pixel size via resize, then adjust the DPI tag here.

Steps

  1. Upload an image (JPG / PNG / TIFF)
  2. View current DPI (typical screen images: 72 or 96 DPI)
  3. Enter target DPI (300 for print; 600 for fine-print)
  4. Optional: also modify the physical size dimensions in mm/inch
  5. Export with new DPI metadata

FAQ

Does higher DPI mean sharper?
Not by itself. DPI is 'pixels per inch' but actual sharpness depends on total pixel count. A 1000×1000 image at 72 vs 300 DPI is the same pixels — only the metadata tag differs. To truly print sharper, you must increase pixel count via resize.
Why does my print shop require 300 DPI?
Print shops calculate required pixels from DPI × physical size. A4 (210×297mm, 8.27×11.69 inch) at 300 DPI requires 2480×3508 pixels. Submitting fewer pixels prints blurry, regardless of DPI tag.
Does changing DPI change file size?
Barely — DPI is metadata (a few bytes). Pixel data is unchanged, file size essentially identical.
How do I actually upscale for print?
Use the resize tool to scale to target pixel dimensions, then use this tool to set the DPI tag. Note: upscaling beyond original pixel count uses interpolation and softens — best to start from a high-resolution source.
Does PNG have DPI?
PNG has a pHYs chunk recording physical resolution, but many viewers ignore it. JPG / TIFF DPI metadata is more universally recognized in print workflows.

Use cases

  • Print shop requires 300 DPI metadata
  • Magazine / publication image submission
  • Poster / business card print preparation
  • Formal document figures
  • Art portfolio submission

Use cases

DPI metadata change (72 → 300 print standard). True print sharpness needs pixel count — resize first, then set DPI tag.