by comparison

When judged against something else. The film was enjoyable, but it pales by comparison to the 1975 original. Her writing is so strong that I feel like mine just pales by comparison. When you consider these two options, one is clearly superior by comparison.

in comparison

When judged against something else. Typically used in the phrase "pales in comparison." The film was enjoyable, but it pales in comparison to the 1975 original. Her writing is so strong that I feel like mine just pales in comparison. What am I even doing here? My acting career pales in comparison to these people!

by comˈparison

(written) used especially at the beginning of a sentence when the next thing that is mentioned is compared with something in the previous sentence: By comparison, expenditure on education increased last year.

by/in comparison (with somebody/something)

when compared with somebody/something: The second half of the game was dull by comparison with the first. ♢ The tallest buildings in London are small in comparison with New York’s skyscrapers.