Image DPI Converter
Change JPG or PNG print density without changing pixels, or resample pixels while preserving physical print size. Everything runs locally in your browser.
- Runs in your browser
- No image upload
- Review before download
Upload JPG or PNG
Select one JPG, JPEG, or PNG image. Animated PNG is not supported.
Choose how to change DPI / PPI
Metadata-only is the default; resampling changes pixel dimensions.
PPI describes image pixels per inch for print. A density tag alone cannot add detail.
Review dimensions and print size
Check the predicted pixel and physical dimensions before processing.
Upload an image to see its density and print-size calculation.
Your image bytes remain in this browser and are not uploaded to PicRecast or an external image service.
How to change image DPI or PPI
Upload a JPG or PNG, inspect its density, choose metadata-only or resampling, select a target PPI, review print size, then download the result.
DPI versus PPI
PPI is the number of image pixels per printed inch. DPI describes printer dot placement. Image files commonly store a density value called DPI, but it does not create additional pixel detail.
Change density without changing pixels
Metadata-only updates the JPEG JFIF and parseable EXIF resolution tags or the PNG pHYs chunk. JPEG compressed scan data and PNG IDAT data remain unchanged; dimensions and decoded pixels are preserved.
Resample for a physical print size
Resampling uses new pixels = original pixels × target PPI ÷ source PPI, rounded to whole pixels. It keeps the approximate physical size, re-encodes the image, and requires explicit permission to upscale.
Why 72 to 300 PPI does not add detail
Changing the metadata from 72 to 300 PPI leaves the same pixels in place. It changes their implied print size. Resampling to 300 PPI makes more pixels through interpolation, but cannot reveal detail the source did not contain.
Pixels versus print size
Print size in inches = pixel dimension ÷ PPI. For example, a 3000 px-wide image at 300 PPI is 10 inches wide. A 2000 px height at 300 PPI is about 6.67 inches.
Missing or conflicting source density
A file may have no density, a unitless ratio, or conflicting JFIF and EXIF values. Metadata-only can set a new value; resampling requires you to supply an explicit known source PPI. Conflicting tags are shown rather than silently resolved.
JPG and PNG behavior
JPG and PNG remain in their source format. Metadata-only preserves compressed image data and other parseable metadata. Resampling may discard metadata and color profiles because browser canvas creates new pixels; PNG has no quality slider, while JPEG quality defaults to 90.
Why apps can show different DPI values
JPEG may carry density in both JFIF and EXIF, and these values can disagree. PNG uses a pHYs chunk, which can be unitless or absent. Some apps choose different tags or use a fallback value. This tool shows conflicting or missing metadata rather than inventing one.
When to use Resize Image for Printing
Use this converter when you have an existing image and want to change its density metadata or resample around its current physical size. Use Resize Image for Printing when you need a specific output print size such as 4 × 6 inches or A4.
Private browser processing
The image is inspected and processed on your device. Image bytes are not sent to PicRecast or another image processing service.
Image DPI Converter FAQ
Are DPI and PPI the same?
PPI measures image pixels per printed inch; DPI usually describes printer dots. Image density metadata is often called DPI even when it represents PPI.
Does changing DPI increase image quality?
Changing metadata only does not change pixels or add detail. Resampling creates pixels by interpolation, but cannot recover detail absent from the source.
What if my image has no DPI metadata?
You can set metadata-only density directly. To resample while preserving print size, enter a source PPI you know; this tool does not assume 72 PPI.
Will the print size change?
With metadata-only changes, the same pixel dimensions at a different PPI imply a different print size. Resampling adjusts pixel dimensions to keep approximate physical print size.
Will the image be re-encoded?
Metadata-only retains JPEG scan or PNG IDAT bytes. Resample mode re-encodes pixels. JPEG uses quality 90 by default; browser canvas output may omit source metadata.
Is my image uploaded?
No. Image bytes are processed locally in your browser.