Heart
Female · American English
Warm, expressive American female — the Kokoro flagship voice for narration that feels human.
Voice Details
API Usage
curl -X POST https://easyvoice.ae/api/v1/audio/speech \
-H "Authorization: Bearer ev_..." \
-H "Content-Type: application/json" \
-d '{"model": "kokoro-82m", "input": "Hello!", "voice": "af_heart"}' \
--output af_heart.mp3Best For
Warm, conversational American female — the Kokoro flagship for long-form narration, audiobooks, and explainer voiceover.
Character
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.
Sample scripts this voice handles well
- Audiobook chapter openers and YA fiction narration where the listener needs to feel the narrator is on their side.
- 30-to-60-second product explainer videos for SaaS landing pages — the warm tone reads as trustworthy without sounding salesy.
- Guided meditation, sleep stories, and self-help audio where breath and pacing carry as much meaning as the words.
Best use cases
Also try
Frequently asked questions
Is the Heart voice free to use?
Yes. Heart (af_heart) is part of EasyVoice's free tier — 2,000 characters a day with no signup, 5,000 a day with a free account, no credit card, with a daily reset. On a free account 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.
What languages does the Heart voice support?
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 9 supported languages share the same flat $9.99/mo Pro pricing.
How does Heart compare to ElevenLabs Rachel?
Heart and Rachel (ElevenLabs) sit in the same warm-American-female lane, but the pricing model is night-and-day. ElevenLabs Rachel is gated by a credit-based free tier and Creator pricing scales per character. Heart on EasyVoice is unlimited at $9.99/mo flat on Pro — and free at 5,000 characters a day on a free account for casual users. The realism gap has narrowed a lot; generate the same script with both and judge for yourself. (PlayHT, once the other common comparison, has had its API offline since Dec 31, 2025.)
What's Heart best at?
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).
Can I use Heart commercially?
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.
Does Heart support SSML or pacing control?
Partially. EasyVoice supports SSML-lite on every plan: insert an exact pause with <break time="500ms"/> (up to 3 seconds per break) and fix a word's pronunciation with an inline IPA phoneme override (syntax on the API docs page) or a saved pronunciation rule. Prosody and emphasis tags are not interpreted. Punctuation still does most of the work — commas, em-dashes and ellipses translate to natural pauses, and for most narration well-punctuated input is all Heart needs; her natural pacing is one of her strengths.