Drop support for Internet Explorer

[perliedman]

Note: Support for IE is being dropped in v2.0!

I think it's really time to discuss dropping support for IE8, and also possibly 9 and 10. These browsers are supported by few web sites these days, and for users who really need to support them, we can point to older versions of Leaflet.

Maintaining support for olders IE versions is a pain, and it appears we rarely test it anyway (we broke IE8 in a previous release without noticing and nobody really told us).

[perliedman]

Some discussion on our IE support in this thread: #4745.

[IvanSanchez]

I guess it's time to run this informal poll again?

[mourner]

I'm up for dropping IE8 support, and agree that we can just offer older versions of Leaflet for people who need to support it. Even jQuery no longer supports that version (https://jquery.com/browser-support/), so people using such a browser should expect the majority of the web to be mostly broken.

We should consider dropping support for IE9 and IE10 too. I just fetched the latest data from http://gs.statcounter.com/ and the breakdown is as follows:

• IE 11: 2.7%
• IE 10: 0.11%
• IE 9: 0.11%
• IE 8: 0.17%

All the IE8–10 values dropped by 2x in the last year.

[tomhughes]

I had a look at the openstreetmap.org statistics at the request of @IvanSanchez and our numbers for yesterday are:

• IE 11: 9% (11128 visitors)
• IE 10: 0.1% (99 visitors)
• IE 9: 0.2% (198 visitors)
• IE 8: 0% (4 visitors)
• IE 6: 0% (2 visitors)

I suspect anything before IE9 barely works other parts of the site anyway, if it's actually functional at all.

[BobbyBabes]

True ancient warriors. So brave : "IE 6: 0% (2 visitors)". 😀
Released on March 22, 2001.

[codeofsumit]

I vote for dropping everything below IE11.

[septatrix]

Pinging @mourner because I think a year and a half later it may be time to again discuss this and come to a conclusion?

Edit: Maybe it's also worth discussion dropping support for Safari except the last two versions and Opera (as it has been chromium based for a long time now - same may be valid for Edge Legacy but I think that should be supported until MS decides what to do with it)

[amb26]

I second dropping support for IE < 11 so that we can move forward on issues like #4745 - cheers!

[jonkoops]

In my opinion we can drop support for all versions of Internet Explorer in version 2. Right now the focus for Leaflet is to decrease our giant backlog of issues and PR before deciding what is next in terms of deprecation.

[jonkoops]

Support for Internet Explorer 11 will be dropped on June 15th 2022. I suggest we drop support for Internet Explorer entirely in v2, which should be released after that date.

I propose we move to accept this proposal. @mourner @IvanSanchez @Falke-Design WDYT?

[IvanSanchez]

I suggest we drop support for Internet Explorer entirely in v2, which should be released after that date.

I'd say drop it, into the deepest pit available.

Support for the W3C DOM standards in IE11 is not that bad, so stuff could be backported to IE11later, but only if somebody actually using IE11 complains.

[jonkoops]

My main problem with IE11 is it's crippled support for anything modern JavaScript. Going forward I think our lowest possible compile target should be ES2015.

[mourner]

6 years later, launching another Twitter poll on IE versions: https://twitter.com/LeafletJS/status/1518606186521804800

[Malvoz]

It'll be interesting to see the poll results, however, dropping IE completely means less considerations and an improvement to the overall workflow. People can always use older versions of Leaflet if they want to support IE.

[jonkoops]

If anything dropping support will incentivize people to stop supporting it all together.

"Be the change you wish to see in the world." – not Mahatma Gandhi

[jonkoops]

Another reason why we might want to drop support for Internet Explorer is that our tooling is no longer working in newer versions (see #8204 (comment)). Some dependencies are already held back simply to keep this support around.

[jonkoops]

The final results from the Twitter poll are in, I think we have enough information to make an educated decision. I am personally in favor for dropping it for the following reasons:

• Only 9.7% of responses have indicated the desire to keep supporting Internet Explorer (these users can keep using 1.x).
• We are holding back several dependency upgrades due to the need to support Internet Explorer.
• We can't use more modern and optimizable ECMAScript syntax that allows us to align with modern expectations of developers (such as Classes).
• We have a lot of crufty code around to support older browsers (not just IE), this will allow us to trim down Leaflet instead of shipping this code to browsers that can't do anything with it.
• We have a lot of open issues around Internet Explorer support that can be closed.
• Support for Internet Explorer 11 will be dropped on June 15th 2022 by Microsoft itself.

For that small percentage of users that are still in need to support Internet Explorer, they can simply stick to Leaflet 1.x. I speculate their projects are not likely to be upgraded fast as the whole ecosystem is breaking away from IE. This also provides more fuel to the fire towards their stakeholders to just get rid of this dinosaur of a browser.

[Falke-Design]

I think we should make a V1.9 release with a few fixes with the most important things and then we make a V2 release with dropping all IE versions. BUT we don't add other features from the Roadmap. We have to much open PRs and issues.

[jonkoops]

So in essence we'd just use the 'v2' version as a way to drop support for older browsers without actually adding any new features. I think that is perfectly valid, and it would reduce the impact of the release in terms of massive changes.

[mourner]

So in essence we'd just use the 'v2' version as a way to drop support for older browsers without actually adding any new features. I think that is perfectly valid, and it would reduce the impact of the release in terms of massive changes.

@jonkoops yep, that was my plan for v2 all along :) see #7704 (comment)

[jonkoops]

Sounds good to me 👍

[jonkoops]

I think we're all in agreement here that we want to drop support for all versions of Internet Explorer so I am marking this proposal as accepted.

[jonkoops]

Closing this as we just branched off for v2, so we can consider this resolved.