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Convert an image to 150 DPI
FreeNo uploadNo signupWorks offline
Set the print resolution recorded in your image to 150 DPI - enough for documents read at arm’s length, at a quarter of the file size of 300. The change happens on your device, and the tool tells you plainly whether it rewrote a metadata field or actually resized the picture, which is the part most converters leave out.
How to use Convert Image to 150 DPI
- Choose or drop your image.
- The target is already set to 150 DPI.
- Leave "Set the tag only" selected unless you want the pixels resized as well.
- Click Set resolution and download. The before and after are shown.
Supported formats
- Input: JPG, PNG
- Output: JPG, PNG
What DPI actually is
An image file is a grid of pixels and nothing else. It has no physical size until something decides how many of those pixels go into each inch of paper - and that number is the DPI. It is a single value recorded in the file’s metadata: the JFIF density field in a JPG, the pHYs chunk in a PNG. Changing it changes how large the image prints, not how much detail it holds. A 600 × 600 photo tagged 300 DPI prints at two inches square; tag the same file 72 DPI and it prints at just over eight inches, from exactly the same pixels, and looks coarse.
What this can and cannot do
Setting the tag cannot add detail. If a form rejects your photo as "low resolution" because the pixel count is too small, no DPI value will fix that - you need a larger photo. What the tag does fix is the very common case where the image is big enough but the file says 72 DPI and a checker refuses it on that basis. Most tools that advertise a DPI increase are doing exactly this and not telling you. The Resample option is the other case: it resizes the pixels so the printed size stays the same, which is a real change and is reported as one.
Which resolution to use
The values worth knowing, and when each is right.
| DPI | Used for | A 3.5 × 4.5 cm photo needs |
|---|---|---|
| 72 | Screens and the default when a file records nothing | 99 × 128 px |
| 150 | Documents read at arm’s length; halves the pixel count | 207 × 266 px |
| 300 | The standard for anything printed and inspected closely, and what most forms demand | 413 × 531 px |
| 600 | Fine line art and some archival scanning; rarely needed for photographs | 827 × 1063 px |
Why a form asks for 150 DPI
A document that will be read rather than examined - a scanned form, a supporting certificate - holds up perfectly at 150, and the file is a quarter of the size of the same page at 300. Several portals impose a file-size limit that makes 300 impractical.
Limitations
- JPG and PNG only - WebP, AVIF and HEIC cannot record a resolution.
- Setting the tag does not add detail; a photo too small for the print size will still look soft.
- Some portals ignore the tag entirely and judge by pixel dimensions.
Privacy
Files you choose are read into your browser’s memory and processed on your device; they are not uploaded to a server. Temporary download links are released after use, and the offline cache never stores your documents. More about privacy and limits.
Frequently asked questions
How do I change an image to 150 DPI?
Drop it here and click Set resolution. The file is rewritten with a 150 DPI tag; the pixels are untouched unless you choose Resample.
Does this improve the quality of my photo?
No, and any tool that says otherwise is misleading you. The resolution tag records intended print size. Detail that was not captured cannot be added by changing a number in the file.
My form says "300 DPI" but also gives a pixel size. Which matters?
The pixel size. It is the only one that determines how much detail you actually have. Set the tag as well, because some checkers read it, but get the pixels right first.
Why does my image show 72 DPI?
Because it records no resolution at all, and 72 is what readers assume when nothing is set. Most cameras and phones do not write the field.
Can I set the DPI of a WebP or HEIC?
No. Those formats have nowhere to record it. Convert to JPG or PNG first.
Is my image uploaded?
No. The file is read in your browser and the few metadata bytes are rewritten on your device. Nothing is sent anywhere.
Is it free?
Yes - free, no signup, no watermark.
Related tools
- Check Image DPISee the resolution a photo declares, and the size it will print.
- Change Image DPISet any print resolution, and see what it does to the printed size.
- Resize Image in cmSet an image to a print size in centimetres, at the DPI you choose.
- Resize ImageChange image dimensions in pixels, percent, cm or inches.