Image DPI Changer
Change the DPI tag on a PNG or JPG file (72, 96, 150, 300, 600...) without resampling pixels. Useful for print, Word, InDesign and submitting photos to publishers.
Quick answer: Change the DPI tag on a PNG or JPG file (72, 96, 150, 300, 600...) without resampling pixels. Useful for print, Word, InDesign and submitting photos to publishers.
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Frequently asked questions
- Will changing DPI change my image's pixel dimensions?
- No. DPI is just a number stored in the file header — it tells print software how many pixels make up one inch on paper. The pixels themselves stay untouched, so a 3000×2000 image stays 3000×2000 regardless of whether its DPI tag says 72 or 300.
- What DPI do I need for print?
- 300 DPI is the industry standard for offset and digital print (magazines, books, business cards). 150 DPI is fine for newspapers and large posters viewed from a distance. 600 DPI is overkill for most jobs but used for fine line art.
- What DPI is best for screens?
- 72 DPI is the historic Mac convention, 96 DPI is the Windows default. Both look identical on screen because browsers and OSes ignore the DPI tag and render based on pixel dimensions only — it only matters when something prints or asks 'how many inches is this?'.
- Will my image quality change?
- Not at all. We only modify the metadata bytes — the actual pixel data is copied through untouched. The new file passes a SHA-256 check on the pixel buffer.
- Why does Word ask me to set DPI?
- Word inserts images at their declared DPI by default. A 3000×2000 photo at 72 DPI becomes 41×28 inches in Word; the same photo at 300 DPI becomes a much more reasonable 10×6.67 inches. Setting a sensible DPI before importing saves you resizing.
- Is my image uploaded?
- No. The file's header bytes are read and rewritten in your browser; the file never leaves your device.
- Can I change DPI on WebP or GIF?
- Not yet — only PNG and JPEG store DPI in a standard, editable header. WebP has a similar mechanism (vp8x) but it's rarely used. For other formats, convert to PNG first.
- Does the file size change?
- It changes by a few bytes (the pHYs chunk is 21 bytes; a JFIF APP0 is 18). Effectively unchanged.
- What's the difference between DPI and PPI?
- PPI (pixels per inch) describes pixel density on screens; DPI (dots per inch) describes ink dots on paper. The file header stores one number that's used by both depending on context — most software treats them as the same.
- Will Photoshop see the new DPI?
- Yes. Open the file in Photoshop and check Image → Image Size; the resolution field will show the value you set, with 'Resample' unchecked so the document size in inches updates automatically.