[2] The producer, Nigel Godrich, recalled of the recording sessions: "People [were] all over the house, shaking things and getting this groove going, then chopping it up into little pieces and putting it back together.

"[3] "Reckoner" features Yorke's falsetto, "frosty, clanging" percussion, a "meandering" guitar line, piano, and a string arrangement by the guitarist Jonny Greenwood.

[4] Yorke said the guitar riff was a homage to the Red Hot Chili Peppers guitarist John Frusciante, "in my sort of clunky 'can't-really-pick' kind of way".

[5] According to the bassist, Colin Greenwood, "reckoner" is an old Biblical word referring to Saint Peter, who judges people at the gates of heaven.

[14] Reviewing In Rainbows, Pitchfork wrote that "Reckoner" was not the "most immediate track", but that after several listens "it reveals itself to be among the most woozily beautiful things the band has ever recorded".

[15] In 2011, Rolling Stone readers voted "Reckoner" the ninth-best Radiohead song, and NME ranked it the 93rd-best track of the preceding 15 years.

[18] In 2020, the Guardian named it the third-best Radiohead song, writing: "At first innocuous, 'Reckoner' unspools a full house of virtuoso performances engulfed by Godrich’s winter-blanket production.