✓ No upload — runs entirely in your browser

DPI Converter — Change Image DPI Online, Lossless

Check the current DPI of any JPG, PNG, WebP or TIFF and change it to 72, 150, 300, 600 or any custom value. Convert one file or a whole batch — multiple files download as a ZIP. 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 JPG (JFIF + EXIF headers), PNG (pHYs chunk), TIFF (IFD resolution tags) and WebP (EXIF chunk). Batch mode: drop up to 50 files, get a ZIP.

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.

DPI to pixels calculator

Enter a print size and DPI to see exactly how many pixels your image needs — or check what your current pixels can print at. The math: pixels = inches × DPI.

Width

Height

Unit

DPI

Common answers at a glance (300 and 600 DPI):

Print size	Pixels at 300 DPI	Pixels at 600 DPI
4 × 6 in (10×15 cm)	1200 × 1800	2400 × 3600
5 × 7 in	1500 × 2100	3000 × 4200
8 × 10 in	2400 × 3000	4800 × 6000
A4 (210 × 297 mm)	2480 × 3508	4960 × 7016
US Letter (8.5 × 11 in)	2550 × 3300	5100 × 6600
Passport 2 × 2 in	600 × 600	1200 × 1200

If your image has fewer pixels than the table asks for, changing the DPI number alone will not add detail — use the Upscale Image tool to genuinely increase resolution first, then set DPI here. Setting 300 DPI or 600 DPI rewrites the print-density header losslessly. Background reading: what DPI actually is and DPI for academic journals.

Which DPI do you need?

Use case	DPI to set
Print shops, photo labs, posters	300
Academic journals & publishers	300 (some ask 600 for line art)
Government / visa photo portals	300 (often stated as "600 × 600 px at 300 DPI")
Large-format banners viewed at distance	100–150
Web and screen use	72 (purely conventional)
Embroidery / engraving services	as 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. TIFF resolution tags and WebP EXIF density are also supported.

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.

Can I change the DPI of multiple images at once? ▼

Yes — select or drop multiple JPG, PNG, WebP or TIFF files and they are all converted to the chosen DPI in one pass, then downloaded together as a ZIP file. Everything runs locally in your browser, so batches process instantly with no upload queue.

How do I check the DPI of an image online? ▼

Drop the image into this tool — it reads the DPI directly from the file header and displays it immediately, before you change anything. No upload required, no software to install. If the image shows 72 DPI but you need 300 DPI for printing or journal submission, click Convert to update the header in one step.