🖨️ Image DPI Modifier
Losslessly change DPI metadata for JPG and PNG in your browser: simultaneously writes PNG pHYs, JPEG JFIF, and Exif IFD0 while preserving ICC / EXIF / XMP. Includes 72 / 96 / 150 / 300 / 600 presets plus scenario presets for ID photos, print shops, Taobao main images, and thesis submissions. Input files are not uploaded by the tool.
Drop JPG / PNG here, click to browse, or paste directly
Batch supported. 25 MB per file max. Images are not uploaded by the tool.
What is DPI? Should I change pixels or metadata?
DPI (dots per inch) does not change the number of pixels in the image. It is a number stored in the file header telling printers "how many inches wide should this print." Changing from 72 to 300 DPI does not make the image sharper — it just makes the same pixels print smaller and denser.
Use "metadata only" when: the print shop / ID photo / thesis submission demands 300 DPI but your file reports 72 DPI. This is lossless and instant. Use "resample pixels" when: you want the pixel count itself to grow or shrink to a target print size, accepting the quality impact of re-encoding.
Typical DPI values
- 72 DPI — web display (Taobao main images also require 72)
- 96 DPI — Windows / Office default screen density
- 150 DPI — entry-level print, draft images
- 300 DPI — professional print / ID photos / SCI color submissions
- 600 DPI — high-detail B&W line art, academic B&W submissions
Why dual-write JFIF + Exif?
JPEG can store DPI in two places: JFIF APP0 and Exif APP1 IFD0. Most tools only update one, leaving the other stale — Photoshop and print shops then read an outdated value. When both exist, we write both to the same value to eliminate that silent-bug.
What does the DPI conflict chip mean?
If JFIF and Exif in your JPEG disagree (e.g. 72 vs 300), your file was processed by a sloppy tool before. We show both values; clicking "Apply DPI" unifies them to the target.
Free in-browser image DPI modifier: losslessly change DPI metadata for JPG and PNG. We write to PNG pHYs, JPEG JFIF APP0, AND Exif APP1 IFD0 simultaneously — most tools only update one and leave the other stale. Default "metadata only" mode does not re-encode or strip ICC / EXIF / XMP. Optional pixel resample path uses browser Canvas with high-quality smoothing. Presets: 72 / 96 / 150 / 300 / 600 plus ID photo, print shop, Taobao main image (72), thesis submission (300/600). X / Y can be unlinked. Batch drop multiple files. JFIF vs Exif conflicts are flagged. Dark mode and one-handed mobile layout. Input files are not uploaded by the tool.