What is the difference between 72 DPI and 300 DPI?

72 DPI is a legacy screen convention; 300 DPI is print density. A 3000×2000 px photo prints at 10×6.7 inches at 300 DPI, but the same file at 72 DPI is interpreted as 41.7×27.8 inches — blurry when printed. Same pixels, different printed size.

Print-ready images · right in your browser

Image DPI Converter

Convert image to 300 DPI (or any value) online — free and lossless. Check the current DPI of any JPG or PNG, set a new one, and download. Your files never leave your browser.

100% private — no upload Lossless — pixels untouched Free — no signup, no watermark

Target DPI:

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JPG & PNG · up to 50 files · checked & converted instantly, never uploaded

How to convert an image to 300 DPI online

Add your images

Drop JPG or PNG files above. The current DPI of each image is detected and shown instantly — this doubles as a free DPI checker.

Choose the target DPI

Pick 300 DPI — the print standard — or 72, 150, 200, 600, or any custom value your print shop, journal, or marketplace requires.

Download

Click Download. The DPI metadata is rewritten losslessly on your device: pixels are untouched, quality is identical, and nothing is uploaded.

What is DPI — and why it doesn't change your pixels

DPI (dots per inch) is a single metadata value that tells printers how densely to place your image's pixels on paper. A 3000×2000 px photo contains exactly the same pixels at 72 DPI and at 300 DPI — the only difference is the intended print size: 41.7×27.8 inches versus 10×6.7 inches.

That's why this image DPI converter never re-encodes your picture. It rewrites the resolution fields (JFIF & EXIF for JPG, the pHYs chunk for PNG) and leaves every pixel byte exactly as it was. Tools that "convert DPI" by re-saving the image quietly degrade quality — there is no reason to.

Print size at 300 DPI — quick reference

To print sharp at 300 DPI, your image needs roughly these pixel dimensions:

Print size	Pixels needed @ 300 DPI	Common use
4 × 6 in (10×15 cm)	1200 × 1800 px	Standard photo print
5 × 7 in (13×18 cm)	1500 × 2100 px	Portrait print
8 × 10 in (20×25 cm)	2400 × 3000 px	Framed photo
8.5 × 11 in (US Letter)	2550 × 3300 px	Documents, KDP interiors
A4 (21 × 29.7 cm)	2480 × 3508 px	Posters, printables
12 × 18 in	3600 × 5400 px	Large prints

Drop an image into the tool above and it shows the exact print size at your chosen DPI automatically.

Image DPI calculator — pixels ⇄ print size

Use this quick image DPI calculator to see how large your photo will print, or how many pixels you need for a target print size.

Pixels: × at DPI:

Print size (inches): × at DPI:

Who needs a 300 DPI image?

Print shops and photo labs, academic journals and conference papers, Amazon KDP book covers and interiors, Etsy printables, embroidery and engraving services, passport and ID photo requirements, magazine ads — all of them routinely reject files whose DPI metadata isn't set to 300. Fixing it takes seconds here and costs nothing.

Frequently asked questions

How do I convert an image to 300 DPI online for free?

Drop your JPG or PNG into the converter above, select the 300 preset and click Download. The DPI metadata is rewritten directly in your browser — free, instant, no watermark, no signup.

Does changing DPI reduce image quality?

Not here. SetDPI only rewrites the DPI metadata (JFIF/EXIF for JPG, pHYs for PNG) and never re-encodes your pixels, so quality is 100% preserved. Many other tools decompress and re-save the image, which degrades quality — this one doesn't.

Will changing DPI change the file size or resolution?

No. The pixel dimensions and file size stay essentially identical. DPI only tells printers how densely to place those pixels on paper — it changes the printed size, not the digital image.

How do I check the DPI of an image?

Drop the image into the tool above — its current DPI is displayed instantly, before any conversion. On Windows: right-click → Properties → Details. On Mac: open in Preview → Tools → Adjust Size.

What DPI do I need for printing?

300 DPI is the standard for high-quality photo and document printing. 150 DPI works for large-format posters viewed from a distance; 600 DPI is used for fine line art. Journals, print shops, Amazon KDP and Etsy printables typically require 300 DPI.

What's the difference between 72 DPI and 300 DPI?

72 DPI is a legacy screen convention; 300 DPI is print density. A 3000×2000 px photo prints at 10×6.7 in at 300 DPI, but at 72 DPI it's interpreted as 41.7×27.8 in — and looks blurry on paper. Same pixels, different printed size.

Can I change the DPI of a PNG?

Yes. PNG stores print density in its pHYs chunk, and SetDPI writes it losslessly — just like the JFIF and EXIF resolution fields in JPG files.

How do I change the DPI of an image without Photoshop?

You don't need Photoshop. This free image DPI changer runs in your browser: drop your JPG or PNG above, pick or type the DPI you need (300 for print), and download. Pixels stay untouched, so there's zero quality loss.

Are my photos uploaded to a server?

Never. Everything runs locally in your browser with JavaScript — files never leave your device, and the page even works offline once loaded.