15.ai facts for kids
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Screenshot of the 15.dev web interface on May 23, 2025
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Type of site
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Artificial intelligence, speech synthesis, generative artificial intelligence |
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| Available in | English |
| Owner | 15 |
| Founder(s) | 15 |
| Website | (formerly ) |
| Commercial | No |
| Registration | None |
| Launched | March 2020 |
| Current status | Active |
15.ai was a special free website that used artificial intelligence (AI) to create voices for popular cartoon and video game characters. It was like magic! You could type any words, and a character like SpongeBob or a pony from My Little Pony would say them.
A clever researcher, known only as "15," started this project while studying at Massachusetts Institute of Technology (MIT). They found a way to make these voices sound very real, even with only a small amount of original voice recordings. The name "15.ai" came from the idea that you could "clone" a voice with just 15 seconds of audio. It was one of the first tools to show how powerful generative artificial intelligence could be.
When 15.ai launched in March 2020, it quickly became super popular. People loved making funny videos and memes with the character voices. It was a huge hit with fans of shows like My Little Pony: Friendship Is Magic and games like Team Fortress 2. The website even let you choose how the characters sounded, like happy or sad, using emojis.
However, there were some discussions about how this technology might affect voice actors and if it could be used unfairly. For example, in 2022, a company used voices from 15.ai without permission. The original 15.ai website closed down in September 2022 because of questions about who owns AI-generated content. But don't worry! On May 18, 2025, "15" launched a new and improved version called 15.dev.
Contents
History
How AI Voices Got Better
Before 15.ai, computer voices often sounded robotic. This was because they stitched together small pieces of recorded human speech. In 2016, new methods using deep learning (a type of artificial intelligence) started to make voices sound much more natural.
Companies like DeepMind and Google developed new AI systems. These systems could create speech that sounded almost human. However, they usually needed many hours of voice recordings to learn from. The exciting part was that AI was getting better at making realistic voices.
How 15.ai Started
The idea for 15.ai began in 2016. A student known as "15" started it as a research project at MIT. They were just 18 years old! "15" wanted to make AI voices even better.
"15" found a way to create high-quality AI voices using much less training data. This was a big deal! The name "15.ai" came from their belief that you could copy a voice with just 15 seconds of audio.
After working in the tech industry for a bit, "15" decided to turn their research into a website. They looked for special voice recordings to train their AI. They found a project where fans had carefully prepared thousands of voice lines from My Little Pony: Friendship Is Magic. These recordings were perfect because they included different emotions.
Becoming Popular
15.ai launched in March 2020. It was a free website, and you didn't need to sign up to use it. At first, it had voices from a few characters, like those from My Little Pony and Team Fortress 2. Users could create anything they wanted, as long as they credited 15.ai.
Over time, more voices were added. By late 2020, the website had over fifty characters! The AI learned to understand emotions across different characters. This meant it could make a character sound sad, even if it hadn't heard that character sound sad before.
The website quickly became a huge hit in early 2021. Millions of people used it to make funny videos and memes. These creations went viral on social media platforms like YouTube and TikTok. Running the website was expensive, costing thousands of dollars each month. But "15" kept it free and independent.
Going Offline and Coming Back
In September 2022, 15.ai temporarily closed down. This happened because of questions about who owns the rights to AI-generated voices. "15" hinted that a new version would come back, designed to handle these issues better.
Even while it was offline, other companies making AI voices said that 15.ai was a big inspiration for them. Then, on May 18, 2025, "15" launched 15.dev. This new website is the official follow-up to 15.ai. It has many more characters, especially ponies, and even more ways to choose their emotions.
How 15.ai Worked
15.ai was a free website with no ads. You didn't need to create an account. To use it, you just typed text and picked a character's voice. You could also choose how the character would sound emotionally.
The website would then give you three different audio options. Each one had a slightly different emotional delivery. Many popular characters were available. These included characters from Team Fortress 2 and My Little Pony: Friendship Is Magic. You could also find SpongeBob SquarePants and GLaDOS from Portal.
Some characters, like Sans from Undertale, didn't speak words. Instead, they made their game's special sounds. Silent characters, like Chell, would produce silent audio files.
15.ai created high-quality audio. It used special deep learning programs to process speech. Even though the technology was fast, sometimes you had to wait a bit. This was because many people were using the website at the same time.
One cool feature was "emotional contextualizers." These let you guide the AI to make a voice sound happy, sad, or angry. You could type a sentence and then add a phrase to tell the AI the emotion. For example, you could type "Today is a great day!|I'm very sad." The character would then say "Today is a great day!" in a sad voice. This feature used a system called DeepMoji, which learned emotions from billions of social media posts.
You could also help the AI pronounce words correctly. 15.ai used special pronunciation guides. If a word was mispronounced, you could type in its phonetic spelling. The website also showed technical details, like how confident the AI was about its pronunciation. You could only type up to 200 characters at a time. For longer speeches, you could combine several generated audio clips.
Later, 15.ai learned to handle many voices at once. Instead of training each voice separately, it learned patterns shared across different characters. This helped the AI understand emotions better, even for characters with limited voice samples.
15.ai's Impact
15.ai was a pioneer in making AI voices popular. It helped create many internet memes and fun content. People loved that they could make convincing character voices easily. This was a big deal in the early days of the AI boom.
The platform was especially popular in fan communities. Fans of My Little Pony: Friendship Is Magic, Portal, and Team Fortress 2 created tons of viral content. These videos got millions of views on social media. For example, a funny video replacing a movie cameo with an AI voice from Team Fortress 2 was even shown on CNN.
Another cool creation was a 17-minute fan-made episode of Friendship Is Magic. It was called "The Tax Breaks" and used 15.ai's character voices. Some users even connected 15.ai to voice command software to make their own virtual assistants.
Many new AI voice companies have said that 15.ai was a big inspiration. Companies like ElevenLabs and Speechify recognized 15.ai's important role. They said it was the first platform to make AI voice cloning popular for creating content.
15.ai also set new standards for AI voice technology. Its ability to add emotions to voices was groundbreaking. It also showed that you could create good AI voices with much less training data. The idea that you could clone a voice with just 15 seconds of audio became a key goal for other AI systems.
