Does it matter if I CAPITALISE my call to action?

[rounasi]

I’m keen to know if there is any research/thoughts on the text formatting of the main call to action which affects the conversion rate optimisation!

Thanks in advance.

[rpkamp]

For their material design, Google states:

By default Material uses capitalized button text labels (for languages that have capitalization). This is to distinguish the text label from surrounding text. If a text button does not use capitalization for button text, find another characteristic to distinguish it such as color, size, or placement.

See https://material.io/design/components/buttons.html

[miriamguimel]

You can certainly use all caps in buttons, though, because buttons by nature contain short segments of text. In general, adding some letter-spacing increases readability, so feel free to use this trick

[SamA74]

Another thing to note for accesibility reasons, don’t type in caps. Use case as you normally would for the text then use CSS text-transform: uppercase to make it display as caps.

From a design point of view I think it looks OK on buttons like that.
But I have seen many cases of inappropriate use of caps where it screams bad design.