✓ No upload — runs entirely in your browser

DPI Converter — Change Image DPI Online, Lossless

Check the current DPI of any JPG or PNG and change it to 72, 150, 300, 600 or any custom value. The conversion rewrites only the file header — pixels are never re-encoded, so there is zero quality loss. No upload, no account.

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No file uploads, ever No account required 100% free Works offline

Convert your image DPI

Read current DPI, set a new one, download

Lossless for both JPG (JFIF + EXIF headers) and PNG (pHYs chunk).

What DPI actually is (and why tools get it wrong)

DPI (dots per inch) is not resolution — it is a printing instruction stored in the file header. The same 3000-pixel-wide photo can claim 72 DPI or 300 DPI while containing identical pixels. Many online "DPI converters" re-encode your image through a quality slider to change this one header value, degrading the image for no reason. This tool edits the header bytes directly: the JFIF density field and EXIF resolution tags for JPEG, the pHYs chunk for PNG. Your image data passes through untouched.

How to change the DPI of an image

Upload a JPG or PNG

The tool reads the current DPI from the file header and shows it.

Choose the new DPI

300 for print and journals, 150 for large-format, 72 for screen. Or type any custom value.

Lossless header rewrite

Only the density header changes — JFIF and EXIF resolution fields for JPEG, the pHYs chunk for PNG. Pixels are untouched.

Download

Same image, same quality, new DPI — accepted by print services and submission systems.

Which DPI do you need?

Use caseDPI to set
Print shops, photo labs, posters300
Academic journals & publishers300 (some ask 600 for line art)
Government / visa photo portals300 (often stated as "600 × 600 px at 300 DPI")
Large-format banners viewed at distance100–150
Web and screen use72 (purely conventional)
Embroidery / engraving servicesas specified — use the custom field

Why this DPI converter

🖨 Truly lossless

Unlike tools that re-encode the image (and degrade quality), this rewrites only the metadata header. Every pixel byte stays identical.

🔍 Shows current DPI

See what DPI your image claims before changing it — useful when a submission system rejects "low resolution" files.

🔒 No upload

DPI conversion happens in your browser. Print-ready artwork and documents never leave your device.

⚡ Instant

No queue, no processing wait — header rewrite completes in milliseconds even for 50 MB files.

Frequently asked questions

Does changing DPI change image quality?
No. DPI is metadata — an instruction telling printers how many pixels to place per inch. Changing it does not add, remove or alter pixels. A 3000 × 2400 px image at 300 DPI prints 10 × 8 inches; the same pixels at 150 DPI print 20 × 16 inches.
Why does a journal or print service require 300 DPI?
Their systems read the DPI header to estimate print quality. If your photo has enough pixels but the header says 72 DPI, automated checks reject it. Setting the header to 300 DPI fixes the rejection without touching the image.
How many pixels do I need for 300 DPI printing?
Multiply inches by 300: a 4 × 6 inch print needs 1200 × 1800 px; 8 × 10 needs 2400 × 3000 px. If you have fewer pixels, the Upscale tool can enlarge the image first.
Does this work for PNG files?
Yes — PNG stores density in a pHYs chunk, which this tool writes correctly (including CRC). JPEG files get both JFIF and EXIF resolution fields updated.
Can I see the DPI of my image before converting?
Yes — as soon as you drop the file in, the tool reads and displays the current DPI from the header. Files with no density header default to 72 DPI in most software.

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