Inconsistency: Meta description character length

[stefanvd]

When creating a new browser extension you need to have a product name and description text. However, there is inconsistency with the length of the description text in the manifest.json file. As a result, there is no universal browser extension description text that is common for all web browser platforms.

Google Chrome (= Microsoft Edge = Firefox)
In Google Chrome the description text is limited to 132 characters:

A plain text string (no HTML or other formatting; no more than 132 characters)

Source: https://developer.chrome.com/docs/extensions/mv2/manifest/description/

Safari
In Safari the description text is limited to 112 characters:

See the screenshot here above.

Resources:

• https://developer.chrome.com/docs/extensions/mv2/manifest/description/
• https://wiki.mozilla.org/Marketplace/Add-ons/Validation

[carlosjeurissen]

Nice catch! It seems the limit of 132 is not enforced in the Chrome browser. I was able to load an extension with a description length of 2500. This applies to the name and short_name properties as well. Funny note, is the minimum length. For the name and description properties, an empty string with length 0 is allowed. Yet, short_name requires at least one character.

Unlike the browser, the Chrome Web Store actually does enforce certain limits. Which could be the 132 description length. For the name and short_name this is a maximum of 45 characters.

@stefanvd the error from Safari, is it when loading the extension or when trying to submit it to their store? Conclusion: It's the app store which rejects such extensions.

Going forward

For extension developers and stores, it's very much preferred to have clear documented limits and preferably synchronized across browsers and stores.

Please note the values could be localised using the MSG_ID syntax. Translated strings in some languages can be a lot longer in terms of length compared to English.

We should clearly figure out and document what each restriction and requirement at this moment of time is in each extension store and browser. This can then be followed with a safe length range which extension developers should be able to rely on.

Additionally, we should consider emojis being part of the value for these properties. As well as special characters like ™. These are not supported at the moment in the Whale extension store. See: https://forum.whale.naver.com/topic/39748/.

It would be very helpful to get more documentation on the difference between requirements from the browser and those from extension stores.

Manifest v4 / extension store proposal

To make sure current manifest v2 and v3 extensions can be loaded fine in new environments, adding additional restrictions only makes sense in manifest v4 or as extension store upload requirement.

My suggestion is to require at least a description and short_name length of 1, otherwise the properties can just be skipped. This is if the description property is really optional (see unresolved issue #100).

The short_name length should not exceed the name length when both don't contain a localised variable. Since this would indicate a developer error.

It would also make a lot of sense when the name property requires at least a length of 1. Otherwise we should make the extension name an optional property (which can be considered).

Lastly, we can explore increasing the character length and synchronize it between browsers and stores.

Clear example how long values are not considered

[stefanvd]

@carlosjeurissen Yes, that is on submitting to the AppStoreConnect. When the processing is done at the Apple server, I receive an email that said, "has one or more issues".