They  say age is just a number, but to a  few select celebrities, it feels like that number hasn't changed in years. Stars like Kate Hudson, Pharrell Williams and Gwen Stefani have all seemingly discovered the fountain of youth, showing little to no signs of ageing over the past decade and while many have resorted to plastic surgery, these A-listers are still sporting glowing taut skin without going under the knife. Here, FEMAIL rounds up the celebrities whose faces haven't changed for at least 10 years. Scroll down for video . 14 years difference: Actress Kate Hudson when she was 22 years old in 2001 (left) and now at 36 (right) Kate Hudson . Although a huge 14 years have passed between the two images, actress Kate Hudson, now 36, looks the same as when she did when she was a young 20-something. Since then, the actress has  won a Golden Globe - for her role in Almost Famous - and has starred in a number of hit films including How To Lose A Guy in 10 Days. The blonde beauty also has two children, one with former husband Chris Robinson, and one with ex-fiancé, frontman of Muse, Matthew Bellamy. Pharrell Williams . 12 years difference: Singer Pharrell Williams when he was 30 years old in 2003 (left) and now at 42 (right) Singer Pharrell Williams has hardly aged a day in the 12 years, but since 2003 has won a whopping 11 Grammys and soared up the charts with hits such Happy and Blurred Lines. He also married longtime girlfriend Helen Lasichanh, and had a son, Rocket, in 2008. Rihanna . 10 years difference: Rihanna when she was only 17 years old in 2005 (left) and now at 27 (right) Despite maintaining her adolescent looks, pop superstar Rihanna has come a long way since she was 17 years old, rising to fame with her third album, Good Girl Gone Bad in 2007. The 27-year-old has now won eight Grammys and also shared a tumultuous relationship with rapper Chris Brown. Jared Leto . 11 years difference: Actor Jared Leto when he was 32 in 2004 (left) and now at 43 . Jared Leto, now 43, has proven his looks are age-defying,  impossibly looking almost younger than he did 11 years ago. The singer and actor has since become an Oscar-winner for his role in Dallas Buyers Club, and has appeared in hit films likeFight Club and the highly-anticipated film Suicide Squad film. Keira Knightley . 12 years difference: Actress Keira Knightley when she was only 18 years old in 2003 (left) and now at 30 . The looks of British actress Keira Knightley have barely changed in the last 12 years, from when she was only 18 years old. Knightley has now starred in award-winning films such as The Imitation Game and Atonement, and is currently pregnant with her first child with husband, musician James Righton. Rachel Weisz . 13 years difference: Actress Rachel Weisz in 2002 at 33 years old (left) and now at 45 . Even though 13 years have passed, Rachel Weisz has managed to maintain her incredible looks, still very much sporting glowing skin and healthy hair. Since 2002, the actress married Bond actor Daniel Craig in 2011, and has one child from a previous marriage. Angelina Jolie . 12 years difference: Angelina Jolie at 27 years old in 2003 (left) and now at 39 (right) Actress Angelina Jolie, now 39, is famed for her bombshell looks, which show no signs of fading even though 12 years have passed between these photos. Since 2003, Jolie has gone on to become Hollywood's highest paid actress, scooping an Oscar, two Screen Actors Guild Awards and three Golden Globes along the way. Jolie is also famed for her humanitarian work and has six children with husband Brad Pitt, who she married in 2014. Jennifer Lopez . 16 years difference: Jennifer Lopez at 29 years old in 1999 (left) and now at 45 . Since 1999, 16 years ago, Jennifer Lopez has appeared in over 18 films, had countless hit songs. She has also been married twice and had a high-profile engagement to the Hollywood star Ben Affleck. He third marriage resulted in two children but you can still see barely any changes to her looks. Mila Kunis . 11 years difference: Actress Mila Kunis at only 20 years old in 2004 and now at 31 . It may have been a whopping 11 years  since 2004, when Mila Kunis was only 20 years old, but the actress' age-defying looks have served her well. Since 2004, Kunis has  appeared in a slew of hit films including Ted and Black Swan, and also married long-time interest Ashton Kutcher, with whom she has one child, born in October of last year. Gwen Stefani . 14 years difference: Singer Gwen Stefani at 31 years old in 2001 (left) and now at 45 . In 2001, Gwen Stefani was only 31 years old, sported dark lip liner and was with her rock band, No Doubt. Fast forward 14 years and despite not seeing any changes to her looks, the singer has enjoyed a successful solo career, a fashion and fragrance line. She also married Gavin Rossdale in 2002, with whom she has three children. And here are the best of the rest: . 21 years difference: Singer Kylie Minogue at 25 years of age in 1994 (left) and now at 46 (right) 14 years difference: Actress Lucy Lui at 32 years of age in 2001 (left) and now at 46 (right) 15 years difference: Actor Keanu Reeves at the age of 35 in 2000 (left) and now at 50 (right) 9 years difference: Singer Leona Lewis at the age of 21 in 2006 (left) and now at 30 (right) 13 years difference: Actress Reese Witherspoon at the age of 26 years old in 2002 (left) and now at 39 (right)
While some  have gone under the knife, these A-listers look effortless.
Many have undergone style and hair changes, but look as young as before.
Some celebrities like Jennifer Lopez still look the same after 16 years.