You can upload photos using the Upload page. Our uploader is HTML5 and doesn’t require any additional plugins. It will support all modern browsers, such as Firefox, Chrome, Safari 6+ or Internet Explorer 9+.
It's best to upload photos at greater than 3000px. This will help ensure great quality on 500px and all of our Apps, as well as the ability to sell your photos in the Store, if you choose to enable that option. You should also use sRGB colour profile when processing and exporting your photos.
Be aware that photos on the upload page will look worse than after you have completed the upload. In order to keep performance fast on the upload page, we reduce the quality of the image.
The DPI of a digital image does not affect its print quality. For more on that topic, read this helpful article.