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This content has been automatically translated from Ukrainian.
Modern iPhones and some Android devices take photos in the format HEIC (High Efficiency Image Coding) <TAG1> is a new image standard that allows you to store quality photos in a smaller size than the usual JPEG. Effective, right? But several important nuances are associated with this format.
Support in browsers
HEIC is not supported by all browsers. For example:
- ✅ Safari (on macOS and iOS) supports HEIC.
- ❌ Chrome, Firefox, Edge — do not support HEIC directly.
That is, if you download a HEIC file to the site and try to show it —, users in most browsers simply will not see images.
Frequent problem: users simply change .heic → .jpg
To pass HTML validation when loading an image (for example, through <input type="file" accept="image/jpeg">), some users just rename the file from photo.heic to photo.jpg.
And unfortunately, the browser can't always detect it right away.
What happens next?
- The server or frontend thinks it's .jpg, but cannot process it.
- Errors may occur when processing an image, generating thumbnails, or when viewing in a browser.
- And worst of all, — such files can "hack" the image pipeline on the site.
What to do (developers)
- On the frontend check not only the file extension, but also MIME-type (file.type).
- Validating on the backend, analyze the contents of the file or use libraries that define the format precisely.
- Warn users about supported formats.
- When jpg download is not working - check mime-type during debugging. This Trojan horse can take time, so it's better to see what's inside right away.
HEIC — is a modern and efficient format, but not yet supported everywhere. Changing the file extension — no format conversion, and it creates more problems than it solves. If you are a — developer, check the format at the content level. If you are a — user, it is better to use a converter than changing the name.
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