How to Change a Photo to 300 DPI for a Form

To change a photo to 300 DPI, open the Change Image DPI tool, choose the photo, tap 300, and tap Change the DPI. The DPI stored in the file changes, and not one pixel of the picture is touched.

If the form also asks for a size, such as 3.5 × 4.5 cm, choose “Make it a print size” instead. That resizes the picture to the right number of pixels for the DPI you choose. This guide explains both, and what DPI really is.

What you need

• The photo (JPG, PNG or WebP) on your phone
• The exact words of the form: does it ask for 300 DPI only, or also a size in pixels or centimetres?
• A minute

Steps to change the DPI of a photo

1. Open the Change Image DPI tool, tap the box and choose your picture. You can choose several at once. The tool shows the pixels and the DPI stored in the file now.
2. Tap 300, or another DPI under DPI. You can also type your own number.
3. Leave Only change the DPI number chosen if the form only asks for a DPI. The line under the options shows the size the picture would print at that DPI.
4. If the form asks for a size, choose Make it a print size instead. Type the width and the height, such as 3.5 and 4.5, choose cm, and decide what to do when the shape is different.
5. Tap Change the DPI and wait a moment.
6. Download the new file. The name ends with the DPI, for example photo-300dpi.jpg. Upload that file.

What DPI means

A digital picture is a grid of pixels, for example 3000 pixels wide and 2000 pixels tall. DPI means dots per inch. It says how many of those pixels are placed in each inch of a print.

A 3000 × 2000 pixel photo printed at 300 DPI is 10 × 6.7 inches. The same photo at 72 DPI would print at 41.7 × 27.8 inches. The picture is the same. The pixels are the same. Only the printed size is different.

This is why changing DPI alone does not make a photo sharper or blurrier. What decides how sharp a print looks is the number of pixels compared with the size of the print.

Two things a form may mean by “300 DPI”

• The number stored in the file. Some forms and printers read it and use it as a hint for the print size. Changing only the DPI number is the right fix. The tool copies the picture data byte for byte and rewrites only the small header that holds the number.
• A size in pixels or centimetres. If the form says “3.5 × 4.5 cm at 300 DPI”, it wants 413 × 531 pixels. A DPI number alone will not give you that. Use Make it a print size, which resizes the picture and stores the DPI.

If you are not sure, read the form again. It often lists a size in pixels as well. If it does, you can also use Resize Image to type the pixels directly.

Common DPI values

• 72 and 96: the old standard for screens. Many photos from phones carry 72 or no number at all.
• 150: a draft print or a scan for reading.
• 200: a scan that must stay readable but small.
• 300: the usual value for photo prints, forms and ID photos.
• 600: fine print scans and detailed line art.

These are common values, not rules. Use the number your form asks for.

For passport and visa photos

Passport photos have exact sizes and other rules, and each office sets its own. Our Passport Photo Maker makes the photo at the right pixel size and stores 300 DPI in it. Always check the official rules of your application. Our guide on making a passport size photo on your phone goes through it.

If the file is too big

Setting 300 DPI does not change the file size. If a form limits the size, use Compress Image afterwards, and then set the DPI again, because compressing makes a new file. Our guide on reducing photo size for forms explains the steps.

Common problems

The form still says the resolution is too low. It probably wants more pixels, not a bigger number. Check the pixels and use a larger original, or a larger print size at the same DPI.

The picture got softer after “Make it a print size”. The photo had fewer pixels than the size needs, so it had to be enlarged. The tool tells you when this happens. Use a bigger original.

HEIC photo cannot be added. Change it to JPG first with HEIC to JPG.

An animated WebP is refused. Only still pictures can be changed.

Frequently asked questions

Does a higher DPI make my photo sharper?

No. DPI only says how many pixels are printed per inch. The detail in the photo does not change. To get more detail you need more pixels in the original photo.

Are the pixels really untouched?

Yes, when you only change the DPI number. The picture data is copied byte for byte and only the header that stores the DPI changes. Our tests check this for JPG, PNG and WebP.

Which DPI should I choose for a form?

The one the form names. If it names none, 300 is the usual value for photos and ID pictures.

Is my photo uploaded?

No. The change happens inside your browser, on your device.