| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 5 | 4 | Guilherme Guido | | 23.00 | Q |
| 2 | 5 | 0 | Shane Ryan | | 23.03 | Q |
| 3 | 5 | 3 | Christian Diener | | 23.15 | Q |
| 4 | 3 | 4 | Kliment Kolesnikov | | 23.16 | Q |
| 5 | 5 | 5 | Evgeny Rylov | | 23.16 | Q |
| 6 | 5 | 8 | Ryan Murphy | | 23.25 | Q |
| 7 | 4 | 5 | Simone Sabbioni | | 23.34 | Q |
| 8 | 3 | 5 | Robert Glință | | 23.38 | Q |
| 9 | 3 | 0 | Matt Grevers | | 23.39 | Q |
| 9 | 4 | 4 | Xu Jiayu | | 23.39 | Q |
| 11 | 4 | 6 | Guilherme Basseto | | 23.46 | Q |
| 12 | 4 | 3 | Mitch Larkin | | 23.49 | Q |
| 13 | 5 | 2 | Apostolos Christou | | 23.57 | Q |
| 14 | 5 | 6 | Dylan Carter | | 23.73 | Q |
| 15 | 5 | 1 | Gabriel Lópes | | 23.75 | Q |
| 16 | 3 | 6 | Viktar Staselovich | | 23.79 | Q |
| 17 | 2 | 5 | Charles Hockin Brusquetti | | 23.80 | NR |
| 18 | 3 | 3 | Cătălin Ungur | | 23.91 | |
| 19 | 4 | 8 | Tomoe Zenimoto Hvas | | 23.96 | |
| 20 | 4 | 7 | İskender Başlakov | | 23.98 | |
| 20 | 5 | 7 | Conor Ferguson | | 23.98 | |
| 22 | 3 | 2 | Thierry Bollin | | 24.06 | |
| 23 | 3 | 8 | Hugo González | | 24.10 | |
| 24 | 2 | 6 | Omar Pinzón | | 24.15 | |
| 25 | 3 | 1 | Andrew Jeffcoat | | 24.17 | |
| 26 | 3 | 7 | Tomáš Franta | | 24.18 | |
| 27 | 4 | 1 | Yuma Edo | | 24.24 | |
| 28 | 2 | 4 | Kang Ji-seok | | 24.54 | |
| 29 | 4 | 9 | Kasipat Chograthin | | 24.63 | NR |
| 30 | 4 | 2 | Mikita Tsmyh | | 24.69 | |
| 31 | 5 | 9 | Adil Kaskabay | | 24.79 | |
| 32 | 2 | 2 | Ádám Telegdy | | 25.03 | |
| 33 | 2 | 7 | Ģirts Feldbergs | | 25.27 | |
| 34 | 1 | 7 | Merdan Ataýew | | 25.30 | |
| 35 | 2 | 3 | Armando Barrera Aira | | 25.38 | |
| 36 | 4 | 0 | Kristinn Þórarinsson | | 25.39 | |
| 37 | 2 | 1 | Tryfonas Hadjichristoforou | | 25.68 | NR |
| 38 | 3 | 9 | Chang Hou-Chi | | 25.85 | |
| 39 | 2 | 8 | Eisner Barberena Espinoza | | 26.45 | |
| 40 | 2 | 0 | Andrianirina Lalanomena | | 27.16 | |
| 41 | 2 | 9 | Bede Mark Aitu | | 27.70 | |
| 42 | 1 | 0 | Omar Alrowaila | | 28.30 | |
| 43 | 1 | 4 | Santisouk Inthavong | | 29.82 | |
| 44 | 1 | 1 | Mohammed Jibali | | 29.90 | |
| 45 | 1 | 9 | Olimjon Ishanov | | 30.50 | |
| 46 | 1 | 5 | Imaan Ali | | 31.16 | |
| 47 | 1 | 8 | Tokelo Makepe | | 34.73 | |
| 48 | 1 | 6 | Yousif Ibrahim | | 34.89 | |
| 49 | 1 | 2 | Alie Kamara | | 36.41 | |
| 50 | 1 | 3 | Hollingsword Wolul | | 37.46 | |
