[x0x0]

reddit tab, firefox: 428mb. same tab, chrome: 78mb.

[mschild]

I get 80mb for reddit on firefox.

That number can be down to any number of different factors on reddit itself. Having an autoplay video running, etc.

[galangalalgol]

Firefox often groups tabs from the same site into one process. With large numbers of the same tabs open in both, check the total memory for all firefox processes and all firefox processes. You will likely find firefox actually uses less memory than chrome.

[x0x0]

The endless excuses and lies.

It was the same page, both on old.

[theodric]

I will eat the RAM penalty to resist the Chromium hegemon. Grateful to have any alternative!

[thunderfork]

Memory measurements reported in browsers come with substantial caveats, as measuring "how much memory is this tab using" is fairly nontrivial.

Not saying there isn't a difference, but you'd need to measure (e.g.) a fresh install viewing only one tab with no extensions, etc.