Cultura Creative (RF) / Alamy Stock Photo

How to tell if an image file size is big enough

Make sure you’re using the right size images for your projects as we talk you through finding the right file size for you. The image size you need will vary from project to project, and it will also depend on whether you are using the image on the web or for print.

To get you started, here are some handy terms you might come across when looking at image file sizes:

Dimensions – a measurement of how big the image will be when it’s printed
Resolution – how much detail an image has. A low-resolution image has a low level of detail and may appear blurry, whereas a high-resolution image has much more detail
Dots per inch (DPI) – the resolution of an image is measured by the amount of detail that will be included in every inch that is printed

1. How to find out what image file size you need

This will depend on how you’re going to use the image. So, the first thing you need to look at is the dimensions and resolution that will be needed for the final image.

As a guide, the recommended resolutions for web and print are:

  • Web-based (online) projects: 72 dpi
  • Print-based projects: 300dpi

For more information on using images in different sized projects, check out our file sizes infographic.

If you’re working on larger scale projects such as a billboard, these will usually be printed at a lower resolution of 150dpi. This is because billboards will be viewed from a distance, so can afford to include less detail than something that will be viewed close-up.

Before you buy an image for a project of this size, we recommend that you check with your printer. They’ll be able to give you the best advice for your individual project.

If you’re not sure what size image you need, get in touch with the Alamy Customer Service team who’ll be happy to help you find the image file size for you!

2. How to find out the maximum file size

If you choose an image that’s too small for your end usage, your only option would be to upsize the image in photo editing software. Making an image bigger than it’s supposed to be will impact the quality of the image as it’ll be stretched beyond its maximum file size. When this happens, an image can become pixelated and appear blurry.

So, once you’ve picked an image, make sure it’s suitable for your project by checking the maximum file size.

Every stock image library will display the information differently, but on Alamy you can find the file size information below the image on the image page. You’ll see the file size displayed in megabytes (MB), and if you hover over the ‘i’ icon, you’ll see the dimensions in pixels and cm, as well as the dpi:

File sizes - image page

If you’re buying a royalty-free license, you pay for the image file size you need by selecting from one of the available image sizes. If you’re buying this way, be sure to buy an image file size that’s big enough for your project. If you’re buying one of our popular pricing licenses, you’ll automatically get the highest resolution available.

Remember: Downsizing an image won’t affect the image quality, but if you buy an image that’s too small for your project and try to upsize it, this will have a negative impact. The larger you try and make an image, the more the quality will be affected and the blurrier it’ll appear.

3. How Alamy can help you find the right file size

1. Test Alamy images in your projects before you buy

We have an awesome tool that lets customers download hi-res files to test in their projects. This is a great way to check the image size is suitable for your project before you spend any money.

For more information on our easy download tool, check this out.

2. Use our handy infographic

We’ve put together an infographic to help select the right size image for your projects at the right resolution. Take a look now.

3. Get advice from our Customer Service team

If you’re not sure what file size you need, our customer service team are on hand to help you out. You can contact them by email, live chat or on the phone.

For more info on image files, check these out:
When and how to upsize an image  
Which image file type do I need?


Alamy is a global digital platform for creatives looking for fresh and inclusive content. Powered by Create search, Alamy delivers fast, catalogued search results, which include editorial photos, vectors, 360-degree images and videos from individual photographers, picture agencies and archives. Its global contributor base supplies upwards of 150,000 new images a day.

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