Female · American English
Warm, expressive American female — the Kokoro flagship voice for narration that feels human.
curl -X POST /api/v1/audio/speech \
-H "Authorization: Bearer ev_..." \
-d '{"input": "Hello!", "voice": "af_heart"}'Heart is the most popular Kokoro voice for a reason: a relaxed mid-range pitch, conversational pacing around 150–170 words per minute, and a slight smile in the delivery that pulls you in without sounding theatrical. She handles long-form narration without the robotic flatness that gives away cheaper TTS, and she scales emotion up gracefully when the script asks for it. Think public-radio host rather than newsreader — measured, friendly, never shouting.
Yes. Heart (af_heart) is part of EasyVoice's free tier — 5,000 characters per day with a daily reset, no signup required to try, and no credit card. That's roughly 750 words of generated audio every day, indefinitely. Most TTS competitors put their flagship female voice behind a paywall; we don't.
Heart is a native American-English voice (en-US). She's tuned for English text and is not multilingual — for Spanish, French, Hindi, or other languages, EasyVoice offers dedicated voices in those locales (e.g. ef_dora for Spanish, hf_alpha for Hindi). All 8 supported languages share the same flat $9.99/mo Pro pricing.
Heart, Rachel (ElevenLabs) and Jennifer (PlayHT) all sit in the same warm-American-female lane, but the pricing model is night-and-day. ElevenLabs Rachel is gated to a 10K-chars/month free tier and Creator pricing scales per character. PlayHT Jennifer is on a similar usage-based plan. Heart on EasyVoice is unlimited at $9.99/mo flat on Pro — and free at 5K chars/day for casual users. The realism gap has narrowed dramatically; for 90% of narration work, listeners can't tell the difference in a blind test.
Long-form narration: audiobooks, course lectures, explainer-video voiceover, and accessibility read-aloud. Heart's strength is sustaining tone across thousands of words without listener fatigue. She's slightly less suited to short, punchy ads where you want energy spikes — for that, try af_bella (more expressive) or am_adam (deeper, more authoritative).
Yes. EasyVoice's terms grant full commercial usage rights to all generated audio, on every plan including the free tier. You can use Heart for paid YouTube videos, paid podcasts, paid courses, paid client work, and paid software products. No per-project licensing fees, no royalties, no attribution requirement.
EasyVoice supports basic pacing control via punctuation (commas, em-dashes and ellipses translate to natural pauses). Full SSML markup support is on the roadmap but not yet shipped. For most narration use cases, well-punctuated input produces better results than SSML anyway — Heart's natural pacing is one of her strengths.