WPT details: https://wpt.fyi/results/css/css-text/white-space?label=master&label=experimental&aligned&view=subtest&q=text-wrap The spec doesn't define the exact algorithm, but requires the number of lines unchanged.
Adjusts the lengths of lines in a paragraph balanced, for better readability and to minimize typographic orphans. This is often useful for headlines. For example: h1, h2, h3, h4, h5, h6, blockquote { text-wrap: balance; } More examplles can be found in a Chrome Developers blog <https://developer.chrome.com/blog/css-text-wrap-balance/>. In addition to the "text-wrap" property, the "white-space-collapse" property is also supported, and the "white-space" property becomes a shorthand of these two properties.
Docs: https://docs.google.com/document/d/16-T9gqCagJxcST6hcnneSb7qGunxXa37_UHYqMqhPL0/edit?usp=sharing