Nick D'Aloisio of Summly, tech reviewer Marques Brownlee, King Bach, Kid President and Tavi Gevinson who started Style Rookie at the age of 12 figure among nos 30-11 of the most exciting people under 30 in digital media, as chosen by the Guardian's 10 trainee digital journalists Matt Andrews , and BuzzFeed's editorial director Jack Shepherd

30. PJ Liguori (@kickthepj) AKA KickThePJ

Age: 23.

What: YouTuber.

Following: 474K on Twitter.

PJ Liguori Photograph: PJ Liguori

Liguori describes himself as a "creative storyteller and connoisseur" and has amassed a YouTube following of nearly 500,000 with his videos of animations, comic sketches and what he calls anti-folk music. He studied at the University for the Creative Arts in Farnham, Surrey, and his films have a creative polish that sets them apart.

29. Marques Brownlee (@MKBHD) AKA MKBHD

Age: 20.

Who: Technology YouTuber.

Following: 1m-plus.

Marques Brownlee Photograph: Marques Brownlee

Brownlee started uploading basic videos when he was 14. Now he's reviewing the latest products – from smartphones to consoles. He has been dubbed the best tech reviewer on the planet, and seriously knows his stuff. His upbeat videos – whether filmed at tech conventions or in his bedroom – offer great insight.

Tavi Gevinson Photograph: Larry Busacca/Getty Images

Age: 17.

Who: founder and editor-in-chief of Rookie Magazine.

Following: 229K on Twitter.

Probably the biggest name on this list, but Gevinson is still only a teenager. She founded her style blog Style Rookie at the age of 12 in 2008, and five years later she's a regular on the front row at fashion shows. She got a generation of teens into blogging.

Reni Eddo-Lodge Photograph: Emilie Fjola Sandy

Age: 24.

Who: Journalist and blogger.

Following: 8.2K on Twitter

A freelance journalist and contributing editor at the Feminist Times, Eddo-Lodge has been a key voice on intersectional feminism. With blog posts called things such as "why I'm no longer talking to white people about race", she has incurred the wrath of Twitter (Louise Mensch, specifically) and fought it off with aplomb.

Conrad Quilty Photograph: Andrew Crowley

Age: 26.

Who: Data journalist at Ampp3d.

Following: 3.5K on Twitter.

He graduated from journalism school in 2010 and three years later was interactive news editor at the Telegraph. He now works as a data journalist at the Mirror group's new data project Ampp3d and is playing a key role in progressing British data journalism.

Rachel Rosenfelt Photograph: Adult Magazine

Age: 28.

Who: Publisher and editor-in-chief of The New Inquiry.

Following: 20.5K for the New Inquiry on Twitter.

In an online world of lolcats and selfies, Rosenfelt and the team at the New Inquiry have managed to build a popular online cultural criticism magazine. Their beautifully illustrated offering contains no adverts and relies on monthly subscriptions.

Jack Rivlin Photograph: Jack Rivlin

Age: 24.

Who: Founder and editor-in-chief of the Tab.

Following: 1.3K on Twitter.

Rivlin is founder and editor-in-chief of the Tab – a group of 34 online student newspapers across the UK. The publication's scoops are frequently picked up by the nationals and, with its mix of tabloid humour and hyperlocal investigative reporting, the Tab is shaking up student journalism.

Liza Dye Photograph: Twitter

Age: 25.

Who: Comedian and prolific tweeter

Following: 2.7K on Twitter.

It's hard to be funny in 140 characters, but Dye does it time after time. She is so well-liked that when she fell in front of a train in February this year, fellow comedians and fans grouped together to raise nearly $60,000 for her medical bills because she didn't have medical insurance.

Laurie Penny Photograph: Jon Cartwright

Age: 27.

Who: Writer.

Following: 88.2K on Twitter.

Penny started her blog Penny Red in 2007, at the beginning of what is loosely referred to as feminism's "fourth wave". In her short, but immensely successful, career she has been nominated for the Orwell prize and has written for pretty much every left-leaning British publication.

Uzoamaka Maduka

Age: 26.

Who: founder and editor-in-chief of the American Reader.

Following: 6K on Twitter.

When Princeton graduate Maduka launched the literary journal American Reader, she was rejecting the idea that "print is dead". Via a partnership with Salon.com, the journal has demonstrated how a beautifully designed, niche print publication can survive alongside digital offerings.

Caroline O'Donovan.

Age: 24.

Who? Staff writer at Nieman Lab.

Following: 887 on Twitter.

Finally, a media commentator who's not a veteran of print journalism. O'Donovan is a staff writer at Nieman Lab, part of Harvard University's Nieman Foundation, which aims to explore the future of journalism in the internet age. BuzzFeed's Jack Shepherd says that her insights are "often absolutely the right insights, which is not a thing that one can often say about tech or media writers".

Jack Harries. Photograph: Can Nguyen/Rex Features

Age: 20.

Who? YouTuber.

Following: 1.83m on Twitter, 3.4m on YouTube.

Harries is a British former child actor who set up his YouTube channel JacksGap to document his gap year for his family and friends. With films of his rickshaw runs in India to partying in Ibiza with his twin brother Finn, he has racked up 3.4 million subscribers – 88% of whom are estimated to be female and between the ages of 14 and 17. Jack's female friends who appear in his videos have received hate mail.

Dylan Sprouse. Photograph: Tiffany Rose/WireImage

Age: 21.

Who? Twitter badass.

Followers: 1.74m on Twitter.

A former child star, Sprouse was once – along with his twin Cole – one of the best-paid child actors in Hollywood. He refers to himself as a "child actor who didn't do meth", an amateur video-game designer and artist, but mainly he's just a really, really good tweeter. When his naked pictures were leaked to the internet, he responded in style: "Whoops, guess I'm not 14 and fat any more." He's got the 140-character quip down to an artform.

Tanya Burr.

Age: 24.

Who? Makeup and fashion YouTuber.

Following: 1.9m on YouTube, 612k on Twitter.

Burr worked on a makeup counter before taking her first steps into video blogging. The 24-year-old from Norwich gained popularity through her weekly beauty tutorials, but has since moved on to product reviews and style tips. She has an incredibly loyal fanbase – a meet-and-greet in Covent Garden, London, last year had to be cut short because the crowds were so huge that organisers were worried people might get hurt.

Andrew Bachelor.

Age: 25.

Who? Comedian and Vine star.

Followers: 179K on Twitter, 300,000 on YouTube, 5.6 million on Vine.

A six-second comedy clip of Bachelor doing a backflip has had nearly two million views – now King Bach even has his own T-shirt line. Besides his millions of followers on Vine, he is big on YouTube, Twitter and Instagram: a real internet all-rounder. Could the Canadian-born actor/director/producer/writer please make up his mind?

Emily Graslie.

Age: 24.

Who? Science communicator.

Following: 20.6K on Twitter.

Graslie started her YouTube channel The Brain Scoop after appearing in a VlogBrothers video by Hank Green in 2012. She's an expert at making complicated scientific ideas easy to understand and is now employed by Chicago's Field Museum as its chief curiosities correspondent, in charge of recording behind the scenes at the museum, and breathing life into dusty exhibits.

Nick D'Aloisio. Photograph: Matthew Lloyd/Bloomberg

Age: 18.

Who? Computer programmer and creator of Summly.

Following: 15.1K on Twitter.

Australian-born British computer programmer Nick D'Aloisio created Summly – an artificial intelligence technology – in 2011 at the age of 15, and sold it to Yahoo! for a reported $30m(£18m) in 2013. He is said to be the youngest person ever to receive venture capital funding, and he was in Time magazine's 100 most influential people of last year. We're basically just very jealous.

Lewis Hancox.

Age: 24.

Who? Multimedia activist behind the film project My Genderation.

Following: 7,885 on Twitter.

My Genderation has been a key voice in the movement to educate and publicise issues around gender variance. Hancox starred, along with his filmmaking partner Raphael Fox, in the Channel 4 reality TV show My Transsexual Summer, which followed seven people undertaking gender affirmation procedures. Hancox's work has helped other young trans people by sharing his story and encouraging them to share theirs.

Suey Park.

Age: 23.

Who? Writer and organiser.

Following: 16.8K on Twitter.

When Suey Park launched her Twitter hashtag #NotYourAsianSidekick, she started a much-needed debate about Asian-American stereotypes. Park argued that she did not feel represented by white feminism, equating "a seat at the table" to a token of diversity. The hashtag trended for days, demonstrating just how much it meant to so many Asian women.

Starting young: YouTube sensation Robby Novak, AKA Kid President, aged just 11.

Age: 11.

Who? Insanely young YouTube sensation.

Following: 187K on Twitter.

It started with a promotional video for the Freed-Hardeman University annual benefit dinner and ended with a million subscribers on YouTube. In his videos, Tennessee-born Robby Novak plays Kid President – a hilarious, pint-sized US president – and his three-and-a-half minute video, Pep Talk from Kid President, has been viewed 31m times. Makes you wonder what he'll do with the rest of his life.