2025 World Championship Previews: A Titanic Battle Is Brewing In The Men’s 100 Freestyle

2025 World Championships

• July 27 – August 3, 2025 (pool swimming)
• Singapore, Singapore
• World Aquatics Championships Arena
• LCM (50m)
• Meet Central
• Live Results
• SwimSwam Preview Index

BY THE NUMBERS – MEN’S 100 FREESTYLE

• World Record: 46.40  – Pan Zhanle, China (2024)
• World Junior Record: 46.86 – David Popovici, Romania (2022)
• Championship Record: 46.80 – Pan Zhanle, China (2024)
• 2023 World Champion – Kyle Chalmers (AUS), 47.15

For the first time in history we have three men who have broken the 47-second mark in the same field, and two of those have broken that barrier already this season. Seven of the eight finalists from Paris return, with Chris Guiliano the only one to miss out after touching third at U.S. Nationals, but we already have six men under the silver-medal-winning time of 47.48 from Paris last year.  In addition, five of the top 10 in history will be in this race – Pan Zhanle, David Popovici, Jack Alexy, Kyle Chalmers, and Gui Caribe.

There are a fair number of familiar names in this field then, but they’ll need to be on the top of their game to make it through to the final again. Fighting for gold though are a pair of transcendent 20-year-olds, who have spent the last 12 months cementing their nascent but already undeniable claims to be counted among the greatest ever in this event.

Pan vs Popovici

Between the two of them, Pan Zhanle and David Popovici own 9 of the 12 fastest times in history in the 100 free, four for Popovici and five for Pan, and are the only swimmers with multiple swims sub-47. With only 13 swims under that barrier ever, the two have a near monopoly at the top, with Caeleb Dressel and Jack Alexy the only swimmers to have done so and be yet to retire.

Pan rewrote the record books in Paris last year, shattering his own World Record by four-tenths of a second. That was his second World Record of the year, as he clipped Popovici’s previous mark with a 46.80 to lead off China’s gold-medal-winning 4×100 free relay at Worlds in Doha back in February.

He also threw down an otherworldly split of 45.92 on China’s medley relay to finish off the Games, the first ever under 46. Add in that he won a first World Championship gold as well in Doha, making him the dual World and Olympic champion, and he carries a ton of momentum into Singapore. His season-best stands at only 47.77, but that was plenty to win Chinese nationals.

After coming into Paris somewhat unproven despite holding the world record, 12 months later he is now the swimmer to beat. He’s now a multiple World and Olympic champion, has shown he can be at his absolute best when the lights are shining, and has a three-tenth gap back to the #2 swimmer all-time. Winning the Olympics from lane four also answered some questions about his ability to fight through the wash from other swimmers, although in a tighter field in Doha he did struggle more. Having gone out in 22.28 on the first 50 in Paris though, he’s got the speed to get out in front.

Popovici finished second behind Pan in Paris, but threw down a 46.88 to win the European Championships earlier in the summer that came within two-hundredths of his best. He was six-tenths slower at the Olympics, but was far from the only swimmer to add time in that final. That was a rebound summer for the Romanian, after he added significantly at Worlds in 2023 and missed the podium in both this event and the 200, a year after breaking the World record in the 100 and setting the world textile best in the 200.

He has been on a tear so far this season as well, dominating the European U23 championships with the second-fastest swim in history in 46.71. That featured the fastest ever second 50 at 23.98 (individually, he also owns the fastest on a relay – 23.94 from last summer), and he looks to be at his best again this summer.

David Popovici (photo: Jack Spitser)t

One feature of his race that could work against Popovici is his tendency to back half the race. That nearly came back to bite him in 2022, where he had his slowest swim of the meet in the final as he fought through the wash of Maxime Grousset next to him, although he did manage to win the race.

The self-proclaimed “skinny legend” is one of the few 100/200 focused swimmers in the field, so will want to avoid the chop from the 50/100 guys around him. He did set a new Romanian record in the 50 earlier this year in 21.83, which he nearly matched in Slovakia to go 21.86, so he could have some additional front-end speed this time around.

He was out 22.73 in Samorin this year however, which means he was out in a 22.7 in all three of fastest swims. If he’s in a centre lane and gets caught up in the wash, his final 50 speed could really be hurt. Conversely, in lanes 1 or 8 he could deliver some serious outside smoke. He should be a lock for the final and has shown an ability to progress through the rounds without overexerting himself, so this is a battle we should almost certainly see.

Aussies Out In Force

Kyle Chalmers completed the sweep at the Fukuoka World Championships in 2023, adding the long course Worlds crown to a trophy case that had featured every other major title. Having been at the top of the 100 freestyle world for nine years now since his surprise Olympic win back in Rio at just 18 years old, and seems to have only improved despite the numerous back, shoulder and heart issues he has faced over that time period.

In what has so far appeared an injury-free year for the Aussie, he ranks fourth in the world thanks to the 47.27 he hit at the Bergen Swim Festival back in April. He neared that time again at Australian Trials in 47.29, and has added even more front-end speed to his game this year. He set a new best of 21.68 to finish second behind Cam McEvoy at Trials, which is three-tenths better than his best of 21.98 from the start of the season. With his ability to throw down 24-low closing splits, going out in a 22-mid could see Chalmers right at the front of the field.

The time zone in Singapore could be a boost for Chalmers compared to some of his European rivals – there is only an hour and a half difference for him, compared to seven hours for them. Having thrown down his fastest two swims ever outside of a major competition this year, the ninth-fastest swimmer in history seems primed for something big.

Flynn Southam took second behind Chalmers at Trials in 47.69, slicing eight-hundredths off his best from 2023. He ranks 10th in the world rankings this season, and matching his best would almost certainly be enough to make the top eight. However, he has only broken 48 seconds twice, both of them at Australian Trials meets next to Kyle Chalmers. He added at Worlds in 2023 to go 48.18/48.15, bowing out in the semi-finals, and had splits of 47.91/48.00 in Paris last year. He would need to be at his best to progress this year.

Watch Out For The Europeans

Despite only three Europeans ranking in this year’s top 10, it would be no surprise if they end up filling out half of the final like they did last year. Behind Popovici it’s Russian Egor Kornev who is the next-fastest from the continent this season, posting a time of 47.42 to win Russian Nationals back in April, and he was recently 47.60 at the Sette Colli. The world short course finalist (5th) has knocked four-tenths off his best this season, and looks to be rounding into fine form for Singapore.

Maxime Grousset has been on the podium in this event in 2022 (silver) and 2023 (bronze), but ended up fifth in his home Olympic games last summer. He set his best time of 47.33 at French Olympic Trials in 2024, and was 47.50 this time around to take top spot. However, he set a brand new personal best and national record in the 100 fly at the same meet, so it remains to be seen how much more time he has to drop in this event this summer.

Maxime Grousset by Bex Wyant

Matt Richards holds a best of 47.45 from Fukuoka 2023, which also stands as the British record, but missed out on the final in Paris after finishing 12th in the semi-finals in 48.09. Since setting that record in the final in 2023 he is yet to break 47.8, and was 47.92 to win British Championships this year for his slowest in-season time since 2022. With the 4×200 free relay, where GB are reigning World and Olympic Champions, coming the day after the final of this event, his focus may be elsewhere.

Germany’s Joshua Salchow was a first-time finalist in Paris, in his first individual swim at World or Olympic level. He’d made incremental gains over the preceding three years, dropping from 49.09 to 47.85, and lowered that further in the final to 47.80, the current German national record. He’s already been 48.02 this year and broke 22 seconds for the first time in the 50 free, and having built perfectly through the rounds last year will be a threat again this time around.

NCAA Stars on the Global Stage

Jack Alexy finished second in 2023, but added significantly from his 47.08 season best to place seventh in Paris in a time of 47.96. He was even faster at U.S. Nationals this year, setting a new U.S. Open record of 46.99 before winning the final in 47.17.

Alexy has had a habit over the last 12 months of adding through the rounds – he has now done so at 2024 U.S. Trials, the 2024 Olympics, 2025 NCAAs and 2025 U.S. Nationals. He delivered his best swim in the final back in 2023 where he took silver in 47.31, and will need to switch his recent pacing around in order to give himself the best chance of making the podium again. He ranks second in the world this year, and 6th all-time, so certainly has the talent to do so.

Patrick Sammon (photo: Jack Spitser)

His teammate this year will be competing for Team USA at his first major International meet. Patrick Sammon came into U.S. Nationals off a great NCAA season which saw him deliver two top-20 all-time 100 free splits, and delivered the swim of his life in the 100 free final to drop four tenths from his brand new PB and outtouch Chris Guiliano for second. His time of 47.47 was a huge improvement from his pre-meet best time of 48.18, and ranks him sixth in the world this season, well under what it took to make the final in Paris (47.94). However, both US men added fairly significantly last year and it remains to be seen how Sammon handles the double taper this summer. If he’s near his best he’ll be in, but he doesn’t quite have the body of work yet that his competitors do.

Gui Caribe, of Brazil and Tennessee, ranks 10th all-time after he threw down a 47.10 at the Maria Lenk trophy to come within two-tenths of Cesar Cielo’s Brazilian record. That was just one more installment in a wildly successful season so far, with short course world silver in the event (with a Brazilian record of 45.47) and a third-place finish at NCAAs where he became the fourth-fastest swimmer ever in yards.

He ranks third in the world this year, and if he can maintain that form should be a serious threat in this field. It is a big if however – as a whole Brazilian swimmers have added in the summer in this event recently, and Caribe has gone out in the semi finals in both 2023 and 2024. If he can minimize any adds or reverse that trend, he could be in the podium hunt as well as make his first major long course final.

The Youngsters

There are several teenagers in the 48-low/47-high range so far this season, who could deliver the sort of drop that puts them in the mix for the final.

Jacob Mills took second at British Trials, dropping well over a second from his best to go 48.03 and make the team along with Matt Richards. He hasn’t broken 49 seconds outside of those Trials however, so we will need to see what he delivers in his first senior international meet. Kim Youngbeom will also break his senior  international duck after going 47.96 at Korean Trials, which was a big drop from his 48.66 previous best which he won Junior Pan Pacs with last summer.

Rafael Fente-Damers (photo: Jack Spitser)

Carlos D’Ambrosio and Rafael Fente-Damers however were both in Paris last summer, D’Ambrosio as a member of Italy’s 4×200 free relay team and Fente-Damers in the individual 100, which he dislocated his shoulder celebrating the qualification of at French Trials. He missed a second swim there, but was 48.02 this year to shave just over a tenth off his best, and did split 47.95 on the medley relay heats. D’Ambrosio set a huge new best of 48.14 at the Sette Colli to qualify at the last minute, but he has a 200 background (1:45.99) that could prove helpful.

The Verdict

Despite not ranking in the top ten this year, Pan is still the swimmer to beat in this event. He had five swims under 47 seconds last summer, and won all three major international finals he competed in – Asian Games, World, and Olympic.

Popovici has had a stellar season so far, but all of his four swims under 47 seconds have come in European outdoor pools – Rome, Belgrade and Samorin – and it is beginning to feel like a trend. Singapore is an indoor pool, and we can’t say with confidence that we can see him replicating his European U23 Championship form. He may have enough for second, but gold could be just out of reach.

Chalmers looks in possibly his best-ever form this year, and his newfound speed in the 50 is no joke – only Caribe, Grousset and Alexy are faster from this field, and none of them have been anywhere close to 1:45.1 in the 200 like Chalmers has. With the 47-low pace he’s shown previously he should be out with the leading pack now as well as closing like a freight train, and his ability to fight through the chop is second to none.

In the end it’s the same podium as in Paris that we’ve picked here. Alexy and Grousset will be looking for repeats of their World medals in 2023, but each face challenges to do so. A 47.9 will not be enough for the final this year, and whoever can manage their energy best through the three rounds could make a splash come July 31st.

SwimSwam’s Picks

Dark Horse: Nandor Nemeth (Hungary) – Nemeth has been quietly consistent in this event over the last few years, making the final at every world or Olympic meet since 2019. He’d been yet to truly contend in those finals until 2024, but after taking bronze in Doha then came within a whisker of a medal in Paris, finishing fourth in 47.50 just behind David Popovici (47.48) and Kyle Chalmers (47.49). He has shown incremental improvements over the years, setting a new best time in every year since 2021 to land at his current best of 47.49, and has the experience and know-how required to make it through the rounds in Singapore. However, he only holds a season best of 48.66 this year and did not compete at Hungarian Trials – if he’s on the team and in the event, he’ll need some big drops from his season best to be in the hunt once again.