"London" by William Blake uses regular rhyme and meter. It consists of four open quatrains rhymed ABAB. Each quatrain consists of four lines of iambic tetrameter, meaning that it is composed of four feet and each foot contains an unstressed followed by a stressed syllable.
"London" uses several other literary devices. The second stanza is a classic example of anaphora, the repetition of the same initial words at the beginning of successive phrases, with the words "In every" being repeated at the beginning of the first, second, and third lines.
There are many other forms of repetition used in the poem, all contributing to a sense of the ubiquity of malign forces. Another example is the use of the word "charter'd" in the first and second lines of the poem, suggesting that not just the streets but even the river Thames are in thrall to commercial interests.