Last updated 09-01-2026
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LMNT
LMNT is an audio generation API for turning text into lifelike speech in live products. It targets conversational apps, voice agents, games, and other experiences where latency and voice quality both matter.
Most text-to-speech APIs cap voice clones or throttle concurrent streams. LMNT includes unlimited voice clones on every API plan, advertises no concurrency or rate limits, and streams audio in roughly 150 to 200 milliseconds. That trade-off favors builders shipping real-time voice rather than batch narration.
The product pairs a free web playground with a developer API. You can preview voices in the browser, then wire the same models into your app through streaming endpoints built for real-time use.
LMNT is built by a small team in Palo Alto with backgrounds at Google[x], Meta, Microsoft, and other startups. The company is backed by investors including Elad Gil and Conviction, and lists SOC-2 Type II compliance on its site. Customers shown on the homepage include Khan Academy, HeyGen, Vapi, Vercel, Unity, and Replit.
Clone a studio-quality voice from a 5-second recording
Generate speech in 31 languages, including mid-sentence language switches
Stream audio with roughly 150-200ms latency for live conversations
Use unlimited voice clones on API plans with no concurrency caps
Try voices free in the web playground before integrating the API
Free playground and API tier make it easy to test voices before committing budget.
Unlimited voice clones on API plans remove a common per-voice billing headache.
Named customers include Khan Academy, Vercel, and Unity, which signals production-grade usage.
Startup Grant covers 15 million characters per month for three months on approved teams.
Usage beyond included characters adds per-thousand-character overage fees on paid tiers.
No standalone mobile app; integration happens through the API or web playground.
Enterprise and custom plans require contacting the team rather than self-serve checkout.
Is LMNT free to use?
Yes. LMNT offers a free web playground for testing voices, plus a free API tier that includes 15,000 characters and unlimited voice clones. Paid API plans start at $10 per month.
How many languages does LMNT support?
LMNT supports 31 languages. The site says its voices can switch languages mid-sentence, similar to how people code-switch in conversation.
How fast is LMNT speech streaming?
LMNT advertises 150-200ms latency for low-latency streaming, which makes it suited to conversational apps, agents, and games that need responsive audio.
Does LMNT offer startup pricing?
Yes. LMNT runs a Startup Grant that provides 45 million credits free for three months, with 15 million characters per month. Teams with fewer than 20 employees can apply through the startup page.
What companies use LMNT?
LMNT lists Khan Academy, HeyGen, Vapi, Fixie, Vercel, Unity, Replit, and Pipecat among the teams using its speech models.
Does LMNT limit voice clones on paid plans?
No. LMNT includes unlimited voice clones on its Free, Indie, Pro, and Premium API plans. The pricing page also states there are no concurrency or rate limits on those tiers.