✓ No upload — runs entirely in your browser

Convert Image to 300 DPI — Free & Lossless

Print services, journals and application portals reject images that aren't 300 DPI. This tool sets your JPG or PNG to exactly 300 DPI by rewriting the file header — pixels untouched, zero quality loss, nothing uploaded.

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

Make your image 300 DPI

300 DPI in one click — quality preserved

The DPI field is preset to 300. Drop the file, click convert, download.

Why your file was rejected for "low DPI"

Automated submission checks read one header value to judge print quality. Cameras and screenshots typically write 72 DPI into that header even when the image has plenty of pixels for sharp printing. The rejection isn't about your image — it's about the label. This tool relabels the file to 300 DPI losslessly. One caveat worth knowing: DPI only matters together with pixel count. A 600 × 400 px image at 300 DPI prints just 2 × 1.3 inches — if a service also specifies minimum pixels, check the table below.

How to convert an image to 300 DPI

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.

Pixels needed for common print sizes at 300 DPI

Print sizePixels required
4 × 6 in (10×15 cm)1200 × 1800 px
5 × 7 in1500 × 2100 px
8 × 10 in2400 × 3000 px
A4 (8.3 × 11.7 in)2480 × 3508 px
2 × 2 in passport photo600 × 600 px
Letter / journal figure2550 × 3300 px

Short on pixels? Use the free Upscale tool first, then set 300 DPI here.

Why convert DPI here

🖨 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.
How do I make a photo 300 DPI for free?
Drop the photo into the tool above — 300 is preset. Click Convert & Download. The header is rewritten to 300 DPI losslessly; the download is instant and free with no signup.

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