Change Image DPI Online
Change the print-resolution (DPI) metadata of a JPEG or PNG directly in your browser. Pixel dimensions and visual quality are never changed, and files are never uploaded to a server.
What this tool does
NexKit Change Image DPI rewrites the print-resolution metadata stored inside a JPEG or PNG file - the number a printer or page-layout program reads to decide how large the image should print. It does not resize, resample, or otherwise touch a single pixel of the image.
This is useful when an image needs to be re-tagged for print (for example, from a 72 DPI web export to 300 DPI) without re-exporting it from its original source, or the reverse.
How the DPI edit works
For JPEG files, the tool writes the DPI value into the image's JFIF header, inserting one if the file does not already have it, or replacing the existing value in place. For PNG files, it writes a pHYs chunk immediately after the image header, using the standard pixels-per-meter encoding that PNG readers expect.
In both cases, the operation is a pure metadata edit: the compressed JPEG scan data and PNG pixel data (IDAT) are copied through byte-for-byte, unchanged.
Supported formats
This tool supports JPEG and PNG, the two common raster formats with a standard DPI metadata field. WebP has no equivalent DPI concept in its file format and is not supported. GIF, SVG, HEIC, AVIF, TIFF, and BMP are also not supported.
This tool updates the JFIF header only. If a source JPEG also carries a separate EXIF resolution value - common in photos re-saved or exported by photo and design software, and present in roughly one in three real-world JPEGs by our own testing - a viewer or tool that prefers EXIF over JFIF may continue to display the prior DPI value even after this tool updates the file.
Privacy and local processing
Images are processed locally in your browser for this tool. NexKit does not upload selected images to a server or store image blobs in browser storage for this workflow.
Frequently Asked Questions
Are my images uploaded?
No. Change Image DPI processes supported images locally in your browser. Files are not uploaded to NexKit servers by this tool.
Does this resize my image?
No. This tool only changes the DPI metadata field. Pixel dimensions, file content, and visual sharpness are never changed.
Which formats are supported?
JPEG and PNG. WebP has no standard DPI metadata field and is not supported. GIF, SVG, HEIC, AVIF, TIFF, and BMP are also not supported.
What DPI values can I set?
Any whole number from 1 to 2400. Common presets (72, 96, 150, 300, 600) are provided as shortcuts, or you can enter a custom value.
Will other tools and viewers see the new DPI?
The DPI is written to the standard JFIF header (JPEG) or pHYs chunk (PNG), which most print, design, and viewer software reads. Some EXIF-aware tools prefer a separate EXIF resolution value over JFIF when a JPEG has both - in our testing, around one in three real-world JPEGs carry that EXIF value, most often photos that were re-saved or exported by photo/design software. Those tools may keep showing the prior DPI even after this tool updates the file.
Can I process multiple images at once?
Yes. Select multiple JPEG or PNG files, apply one shared target DPI, and download the results individually or together as a ZIP.