Ranking The World Records Most Likely To Go Down In Tokyo: Women’s Edition


For a swimmer, the Olympic Games are the most important eight days of competition every four years (five in this case). The goal? Be at your best at the Games, ideally in the final, should you get there.

But that isn’t always the case, as the weight of pressure, expectation, and the surreal feeling of finally being where you envisioned yourself for so many years can hinder an athlete’s performance. On the flip side, some tend to thrive under the lights.

So while it seems as though any swimmer who’s been near a world record over the last few months should be a slam dunk to take it down at the Games, we know it’s not always the case.

With that being said, we do see world records broken at the Games. In 2016, eight all-time marks were broken across seven events. In the five years since the last Olympics, world records have been lowered in 14 events that will be on the program in Tokyo.

So which events are most likely to see world records fall? Below you’ll find a ranking of each world record on the women’s side, ranked in order of least to most likely to be broken in Tokyo. Relays will get their own sub-section. The men’s edition will be coming shortly.


Ranked least to most likely to be broken in Tokyo.

14. 200 Butterfly – 2:01.81, Liu Zige – 2009

This record was set in 2009 and might stand until 2109. China’s Liu Zige was an absolute force in setting the women’s 200 fly world record in 2:01.81 while wearing a super-suit, more than two seconds faster than she was at the World Championships less than three months earlier.

The second-fastest swim of all-time isn’t even within a second and a half (2:03.41), and the quickest textile time is 2:04.06 from Liu’s countrywoman, Jiao Liuyang, at the 2012 Olympics.

Since the 2016 Games, Rio gold medalist Mireia Belmonte is the fastest swimmer in the world at 2:05.26 (she won’t swim the event in Tokyo). Current world #1 Zhang Yufei (2:05.44) is more than three and a half seconds off the pace.

13. 400 Individual Medley – 4:26.36, Katinka Hosszu (HUN), 2016

Katinka Hosszu‘s 400 IM world record swim in Rio was the culmination of four years of frustration, blood, sweat and tears, all delivered in one mind-bending performance.

No swimmer, not even Hosszu herself, has come within two seconds of that swim, and while Hosszu may well defend her Olympic title, she’s not touching that time at 32. Hosszu has only broken 4:30 once—at the 2017 Worlds—since Rio.

Japan’s Yui Ohashi is the next-fastest swimmer who will race in Tokyo with a 4:30.82 from 2018, but she hasn’t been near that time since.

12. 200 Individual Medley – 2:06.12, Katinka Hosszu (HUN), 2015

Not unlike her 400 IM swim one year later, Hosszu had a flawless performance in the women’s 200 IM final at the 2015 World Championships, getting under the seemingly bulletproof super-suited record of 2:06.15 set by Ariana Kukors in 2009.

In Rio, despite being on the best form of her career in other events, Hosszu was 2:06.58 in her fourth individual event of the meet, and hasn’t been sub-2:07 since.

With backstroking star Kaylee McKeown expected to push Hosszu for gold in Tokyo, it’s possible that at least one of them will dip into the 2:07s, but 2:06.1 is way out there and will likely go untouched for a few more years.

It’s also worth noting that Hosszu was 2:07 in all three rounds at the 2019 World Championships, but hasn’t even been under 2:10 (!) since the pandemic hit. We’re entering the Games under the assumption that the greatest medley swimmer of the past decade will be back to her dominant self to some extent, but who knows.

11. 100 Freestyle – 51.71, Sarah Sjostrom (SWE), 2017

Sarah Sjostrom broke ground as the first woman under 52 seconds in the 100 freestyle on the lead-off leg of Sweden’s 400 free relay at the 2017 World Championships in Budapest, but the record has held firm since and doesn’t appear to be seriously threatened in Tokyo. No one else in history has broken 52.

In Rio, the gold medal was won in a time over six-tenths slower than the world record, with Cate Campbell in the field and just a month removed from setting the mark. Sjostrom is returning from injury, Campbell hasn’t been able to swim her best in the biggest moments, and the woman who has dominated major finals in recent years, Simone Manuel, failed to qualify in this event.

Someone like Emma McKeon could take a run at the record, potentially even at the beginning of the meet if she were to lead off the Australian relay, but it would still take a huge best time for her to do so.

10. 50 Freestyle – 23.67, Sarah Sjostrom (SWE), 2019

Three women have broken 24 seconds this season, putting the 50 free record of 23.67 somewhat in play, though still pretty far off given that it’s only a 50.

That trio is made up of McKeon (23.93), Campbell (23.94) and Ranomi Kromowidjojo (23.97), while defending champion Pernille Blume has been close this year in 24.06. But compared to Sjostrom’s 23.67, they’re all still a ways off.

Sjostrom was 24.25 in June, which makes her a contender for gold, but it’s clear she’s not on her 2017 freestyle form.

9. 200 Breaststroke – 2:19.11, Rikke Moeller-Pedersen (DEN), 2013

Interestingly enough, we’ve seen 12 sub-2:20 swims in the women’s 200 breaststroke, but none came during the super-suit era, which peaked in 2009. All 12 of them came between 2012 and 2017, with world record holder Rikke Moeller-Pedersen responsible for five of them.

Since Yuliya Efimova swam a pair of 2:19s in the summer of 2017, the fastest swim we’ve seen is a 2:20.17, done both by Efimova to win the World Championship title in 2019 and South Africa’s Tatjana Schoenmaker earlier this year.

Efimova didn’t qualify to swim the 200 breast in Tokyo, leaving Schoenmaker as the top seed coming in. The 24-year-old has had a steady rise to the top in the event during the quad, including winning gold at the 2018 Commonwealth Games and silver behind Efimova at the 2019 Worlds, but she would need a full second drop to hit the record.

Annie LazorMolly Renshaw and Kanako Watanabe have all been under 2:21, and Lilly King and Russian junior Evgeniia Chikunova could pull out something crazy, but the record appears too far out of reach for the time being.

8. 1500 Freestyle – 15:20.48, Katie Ledecky (USA), 2018

Based on history, it’s fair to say that any Ledecky world record is not safe, especially at the Olympics. Ledecky has an amazing track record at the Games, highlighted by her four gold medals in Rio, which included world records in the women’s 400 and 800 free that still stand.

Ledecky’s 1500 WR came out of nowhere at the Indianapolis Pro Swim in May 2018, and having withdrawn from the event due to illness at the 2019 Worlds, the times she’s raced it fully tapered have come few and far between.

We shouldn’t read too much into the U.S. Olympic Trials, where Ledecky was far from her best, because she didn’t need to be to make the team. But she was 20 seconds off the record in Omaha and hasn’t shown any indication she can seriously take a run at the existing mark.

7. 800 Freestyle – 8:04.79, Katie Ledecky (USA), 2016

The 800 free in Rio was arguably Ledecky’s career-best performance, lowering the world record by almost two seconds on the world’s biggest stage.

With a chance to three-peat in the event, gold looks to be firmly in Ledecky’s grasp as the owner of the 23-fastest swims ever, with anything sub-8:10 likely winning by five seconds. Like the 1500, though, the record is a bit out there based on her recent form.

6. 200 Backstroke – 2:03.35, Regan Smith (USA), 2019

The shock of the U.S. Trials came when world record holder and reigning world champion Regan Smith failed to make the Olympic team in the women’s 200 backstroke, robbing us of her highly anticipated head-to-head clash with Australian Kaylee McKeown.

McKeown is now the odds-on favorite for gold, and though she’s still almost a second outside of Smith’s 2019 record, we can’t put limits on her after a phenomenal year.

Having recently stolen the 100 back world record from Smith, cracking 2:04 for McKeown seems imminent—whether or not she can get down to 2:03.3 is the question.

5. 100 Breaststroke – 1:04.13, Lilly King (USA), 2017

Like McKeown in the 200 back, the 100 breast appears to be firmly in Lilly King‘s grasp, with the defending champion having gone undefeated in the event since Rio and always coming up big under pressure.

King has only been within eight-tenths of her world record since setting the mark in 2017, clocking 1:04.93 at the 2019 Worlds, but she’s shown record-breaking form on the short course scene since we last saw her fully tapered in long course, dominating the ISL in late 2019 and 2020.

This one being ranked so highly is betting on the swimmer more than what the numbers say. King hasn’t been pushed too hard in the event in recent years, but the height of the Games could very well be enough to elevate her to another record.

4. 200 Freestyle – 1:52.98, Federica Pellegrini (ITA), 2009

Given that it’s one of just two remaining female world records from the super-suit era, the women’s 200 freestyle ranking so high is certainly a drastic change compared to where it’s been placed in the past.

The reason? Ariarne Titmus.

Titmus became the first swimmer to put a legitimate scare into this record in 12 years, clocking 1:53.09 at the Australian Olympic Trials in June.

The final will all about the battle for gold, with defending champion Ledecky expected to be Titmus’ biggest challenge. But the form showed by Titmus last month may be too much for even Ledecky to match. She would need a best time by .64 to catch her. And that PB was set five years ago.

Federica Pellegrini, the world record holder, will also be in the field. She produced a magical win at the 2019 Worlds in 1:54.22, but it’s hard to see her going faster than that as she nears the end of her career.

Titmus has performed well in major international competition so far in her young career, and now in Tokyo, she’ll be on the cusp of erasing one of the last remaining super-suit records.

It’s also worth pointing out that Titmus swam what was her previous best time of 1:54.27 on the 800 free relay lead-off at those Worlds in Gwangju, so even if the pressure of the individual final doesn’t produce a world record, she could claim it on the relay if she ends up going first.

3. 400 Freestyle – 3:56.46, Katie Ledecky (USA), 2016

Another one of Ledecky’s standout swims from Rio, the 400 free record seems like it could go down for a few reasons.

First off, it’s at the beginning of the meet, when everyone’s firing on all cylinders and busy schedules and medal ceremonies have yet to interfere with rest and recovery. And secondly, there are two women in contention to break it.

Along with pushing the 200 free record at the Aussie Trials in Adelaide, Ariarne Titmus also did something extraordinary in the 400, registering the second-fastest swim of all-time in 3:56.90. That’s faster than all of Ledecky’s swims other than the 2016 Olympic final, which is huge considering her historical dominance in the distance freestyle events.

Titmus upset Ledecky to win the 2019 World title in this event, ending the American’s run of three straight golds. We later learned that Ledecky was far from 100 percent in Gwangju, but still, that loss is only going to fuel her.

Ledecky’s fastest swim in the event since the beginning of 2019 actually came at the Mission Viejo Pro Swim this past April (3:59.25), better than she was in Gwangju and U.S. Trials. It’s well outside of the record and what will likely be required to win gold in Tokyo, but if Ledecky has taught us anything it’s that logic doesn’t always apply to her. She can never be counted out.

But if Titmus hits her taper, it might not matter. She’s on incredible form, and is showing no signs of slowing down.

2. 100 Butterfly – 55.48, Sarah Sjostrom (SWE), 2016

Sarah Sjostrom was dominant in the women’s 100 fly leading up to the 2016 Games, and punctuated that reign by winning Olympic gold in a new world record of 55.48. That record still stands, but there are several women within range of taking it down in Tokyo.

First we saw Canadian Maggie MacNeil upset Sjostrom to win the 2019 World title in 55.83. Then, China’s Zhang Yufei ripped the third-fastest swim ever, 55.62, in September 2020.

This year we’ve seen Zhang (55.73) back under 56, MacNeil go 56.1 in a time trial, and 18-year-old American Torri Huske produce back-to-back swims of 55.78 and 55.66 at the U.S. Trials. Australia’s Emma McKeon joined the club last month in 55.93, while Sjostrom has been hesitant about even racing the event after coming off elbow surgery.

Whether it’s Zhang, Huske or MacNeil, this one feels like it’s going down soon.

1. 100 Backstroke – 57.45, Kaylee McKeown (AUS), 2021

The lone Olympic event that has seen a world record fall this year, the women’s 100 backstroke has at least two, maybe three, swimmers in contention to break the record.

Regan Smith smashed through the 58-second barrier in 2019, leading off the U.S. medley relay in 57.57 at the World Championships, and then Kaylee McKeown joined her with a pair of sub-58s in-season before lowering the record down to 57.45 in June.

Canadian Kylie Masse, the world champion in both 2017 and 2019, joined them with a 57.70 of her own last month, putting the three of them within a quarter-second of the record entering Tokyo.

Smith went under 58 for a second time at U.S. Trials in the semis (57.92), but tightened up a bit in the final and finished in 58.35. If she can swim a bit freer in Tokyo, she’ll have a shot to reclaim the record, while McKeown has simply been amazing recently and Masse always perform well in major finals.


Ranked least to most likely to be broken in Tokyo.

3. 400 Medley Relay – 3:50.40, United States – 2019

The foursome of Smith, King, Kelsi Dahlia and Manuel were firing on all cylinders when they set this record in 2019, producing a time that no other relay team has come within a second of.

Even with similar back and breast legs, along with an improved fly leg, their freestyle has seen a significant drop-off compared to the form Manuel was on in 2019 (she split 51.86 on this relay). If King and Torri Huske combined to be a second faster than the 2019 team, they might have a shot at it.

2. 400 Freestyle Relay – 3:30.05, Australia – 2018

The Australians have now been 3:30 four times in the 400 free relay, narrowly missing the 2018 world record of 3:30.05 at the 2019 World Championships (3:30.21).

They’ve got the three fastest swimmers in the world this season with Emma McKeonCate Campbell and Madison Wilson, and either Meg Harris, the experienced Bronte Campbell or 2019 relay member Brianna Throssell will provide a solid fourth leg.

If you add up the 2021 flat-start times from McKeon, C.Campbell, Wilson and Harris, their time would be just .25 off of the record. Easily made up with relay exchanges.

1. 800 Freestyle Relay – 7:41.50, Australia – 2019

Just like the 400 free relay, but even more promising.

The add-up of the top-four finishing times at the Australian Olympic Trials in the women’s 200 freestyle comes out under the relay world record by almost two seconds in 7:39.59. That’s led by Titmus’ 1:53.09, but also buoyed by strong showings from McKeon (1:54.74), Wilson (1:55.68) and Leah Neale (1:56.08).

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2 years ago

800m and 1500m free records are just as safe as the IM records. The swimmer who owns them (and could possibly break them) is not in the form to do so. Only thing that Katie is closer to her top form than Katinka, but clearly out of reach.

Lex Soft
2 years ago

Which one is more difficult to break : Ledecky’s 800m free or Zhang Lin’s 800m free ?
The PB of the current best, Gregorio Paltrinieri is 7 seconds behind the Chinese’s WR. We know the WR came from the super suit era, but it was also because of fantastic kick by Zhang Lin in the last 50m. Compared to Paltrinieri’s kick which is always 2 beat most of the time, including in the last 50m when he swam in 1500m final at WC 2019.
Well, I am waiting for Men’s edition for the same article.

Lex Soft
2 years ago

Waiting for men’s edition

2 years ago

Everyone really sleeping on Ledecky big timeeeee.


200 free: 1:53 low
400 free: 3:54
800 free: 8:02
1500 free: 15:16

Reply to  TeamDressel
2 years ago

1:54 low, 3:55, 8:07, 15:26. If she’s absolutely on her A game. So either 3 golds and a podium, or 2 golds, a silver, and a podium, because titmus will shock swimswam if she DOESNT get under the WRs in the 200/400. She’s the one

2 years ago

Not to be a troll or anything but I have some questionable thoughts. I don’t want to say predictions just thoughts.

I could honestly see Claire Curzan swimming like 56.8s in prelims and semis and then ripping like a 54.9 in finals.

I think the womens 100 back world record will go down three (maybe four) times, and I think Kaylee and Regan will battle in the final. I think Kaylee takes it and Regan gets it back on the relay. I think it will end at 56.8

The 200 free progression is wild. It would be #13 or #14 a year ago. Kudos to Titmus, I think she will break it (this one is less crazy).

Last edited 2 years ago by Swimmerj
M d e
Reply to  Swimmerj
2 years ago

These all seem way, way too fast.

2 years ago

100 butterfly goes down and possibly by multiple swimmers.

Probably broken in the semis, which will heighten the drama for the final because several swimmers could re-break it.

2 years ago

This is my order:

200 FL
400 IM
800 FR
1500 FR
200 IM
100 FR
50 FR
200 BR
200 BK
100 BR
200 FR
400 FR
100 FL
100 BK

Hardest is placing 100 and 50 free.

Reply to  Troyy
2 years ago

Yep…thats the order!

2 years ago

I think the 100 free is more likely then elderly beating her one marks in the 800 and 1500 as well as the 100 breast. McKeon’s got a shot at it which will also push Campbell along it will be interesting to see. I think we get another women under 52 which puts the WR in question.

About James Sutherland

James Sutherland

James swam five years at Laurentian University in Sudbury, Ontario, specializing in the 200 free, back and IM. He finished up his collegiate swimming career in 2018, graduating with a bachelor's degree in economics. In 2019 he completed his graduate degree in sports journalism. Prior to going to Laurentian, James swam …

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