Update v5 .browserslistrc

[mdo]

v5 has been around for almost five years (with the first alpha release in June 2020). In that time, browser support for new CSS and JS features has really accelerated, and Bootstrap 5 hasn't progressed to support that.

I'd like to modify the supported browsers in v5.4 to push the project forward to more modern features.

Here's our list today with 96% coverage:

>= 0.5%
last 2 major versions
not dead
Chrome >= 60
Firefox >= 60
Firefox ESR
iOS >= 12
Safari >= 12
not Explorer <= 11
not kaios <= 2.5

Bumping some of these drops us to 94.4%:

>= 0.5%
last 2 major versions
not dead
**Chrome >= 105
**Firefox >= 121
Firefox ESR
**iOS >= 15.4
**Safari >= 15.4
not Explorer <= 11
not kaios <= 2.5

I targeted those versions to at least get :has(), but we may even want to further refine them and see what features we want access to without making folks upgrade to v6.

This in theory also goes well with the Sass modules support which will be a breaking change within v5.

More to come but I wanted to get this out there before I forgot and collect some initial thoughts.

[julien-deramond]

To connect existing elements, the description in https://github.com/twbs/bootstrap/pull/37309 includes references related to a potential update of the .browserslistrc file.

[mdo]

Was looking at some compatibility tables and trying to find what features we'd want to see about adding support for in v5.x. Not exhaustive, but there are a handful if we jump to Safari 15.4-ish and Chrome 100-ish.

Feature	Chrome	Safari	Firefox	Likelihood
popover attribute	114	17	125	🔴
Custom	114	17	125	🔴
color-mix()	111	16.2	128	🟠
Relative colors	119	18	128	🔴 (Safari)
@container and container	105	16	110	🟠
@layer	99	15.4	97	🟢 (but unlikely for v5.x)
@property	85	16.4	128	🟠
:has()	105	15.4	121	🟢
Logical properties	89	15	137	🟢
Range media queries	104	18.4	137	🔴
	37	15.4	98	🟢

[julien-deramond]

The goal was to get a general sense of the ecological impact of supporting Safari 15 and above.

I started looking into this out of curiosity, since I never use Safari myself. But I’ve seen use cases where websites rendered poorly on otherwise perfectly functional Macs less than 10 years old, simply because the sites relied on features only available in more recent browser versions. That made me wonder how non-technical users might be impacted.

To make matters trickier, Safari versions are tied to macOS versions — and macOS updates are often locked out on older Macs. So even if the hardware is capable, users might be stuck with an outdated Safari.

Some features may still work thanks to fallbacks, so a proper assessment would require a feature-by-feature analysis.

Based on this early overview — if the findings hold up — Safari 15.4-ish might be a reasonable baseline to aim for.

[!WARNING]
This overview was generated by AI to give a general sense of the results — I haven’t manually verified it yet.

Apple Devices Stuck Below Safari 15

These devices are found by AI incompatible with Safari 15 or higher, due to OS limitations. By updating our .browserslistrc to Safari >= 15, these users would no longer be supported.

iPhones

Device	Release Year	Last OS Version	Max Safari Version	Notes
iPhone 5	2012	iOS 10.3.4	~Safari 10	No 64-bit support
iPhone 5c	2013	iOS 10.3.3	~Safari 10
iPhone 5s	2013	iOS 12.5.7	~Safari 12	First 64-bit iPhone
iPhone 6 / 6 Plus	2014	iOS 12.5.7	~Safari 12	No iOS 13 support

iPads

Device	Release Year	Last OS Version	Max Safari Version	Notes
iPad 4th Gen	2012	iOS 10.3.3	~Safari 10
iPad mini 2	2013	iOS 12.5.7	~Safari 12	Retina display
iPad mini 3	2014	iOS 12.5.7	~Safari 12	Touch ID added
iPad Air (1st gen)	2013	iOS 12.5.7	~Safari 12	No iPadOS support

Macs

Device	Release Year	Last macOS Version	Max Safari Version	Notes
MacBook Pro (13"/15")	Mid-2012	macOS 10.15 Catalina	Safari 14.1.2	No macOS 11 Big Sur
MacBook Air	Mid-2012	macOS 10.15 Catalina	Safari 14.1.2
MacBook	Early 2015	macOS 11 Big Sur	Safari 14.x	Big Sur supported, but no Safari 15
iMac	2012	macOS 10.15 Catalina	Safari 14.1.2
Mac mini	2012	macOS 10.15 Catalina	Safari 14.1.2
Mac Pro (2010–2012)	2010–2012	macOS 10.14 Mojave*	Safari 14.x	Requires Metal GPU for Mojave

* Only supports Mojave if upgraded with a compatible GPU.

---

Safari 15+ Support Starts With:

Device Class	Minimum Model	Release Year
iPhone	iPhone 6s / SE (1st)	2015
iPad	iPad Air 2 / mini 4	2014–2015
Mac	macOS 11 Big Sur-ready	~2013+

[louismaximepiton]

On our project, we might define the same baseline as the ones in here. We had several discussions about it internally, but we've decided almost the same as yours:

>= 0.5%
last 2 major versions
not dead
Chrome >= 120
Firefox >= 121
Firefox ESR
iOS >= 15.6
Safari >= 15.6
not Explorer <= 11
Samsung >= 23

My main concerns go for:

• Safari, we can set it to 15.6 so it won't break more than 15.4 and still have some newest features inside.
• Samsung 23+ can be safely added I think with the baseline you define

Here is our findings about our .browserlistrc: https://github.com/Orange-OpenSource/Orange-Boosted-Bootstrap/pull/2929

[mdo]

@louismaximepiton Wow amazing PR there with the supported features. Appreciate that! I think we'll end up going that route as well after reviewing your PR another time.

[coliff]

All looks good to me- happy to see the browser support updated!

One minor thing, not Explorer <= 11 can be completely removed from the config - it's not necessary to state that because a) it's browser marketshare is less than 0.5% so it wouldn't be included anyway, and b) it's also excluded as part of the not dead rule.