Report Bug / Feature Request
Voice Cloning Voice Changer AI Narrator AI Dubbing AI Voice Chat Voice Recorder Voice from Text Celebrity Voice Generator More →

AI Voice — OpenAI: GPT-4o Audio

Commercial use OK 380+ models No watermark No sign-up needed
Model:
+ GPT-5, Claude, Gemini
TTS engine Premium
OpenAI: GPT-4o Audio — OpenAI: GPT-4o Audio is an AI model by OpenAI on Free.ai. It supports up to 128,000 tokens of context. Costs approximately 4,781 tokens per message. Try OpenAI: GPT-4o Audio instantly — no sign up needed. Compare it side-by-side with other…
0 characters ~0 tokens
Cost scales with character count
Generating speech...

What does OpenAI: GPT-4o Audio sound like?

OpenAI: GPT-4o Audio is an AI model by OpenAI on Free.ai. It supports up to 128,000 tokens of context. Costs approximately 4,781 tokens per message. Try OpenAI: GPT-4o Audio instantly — no sign up needed. Compare it side-by-side with other models.

Try the box above with: Hello, my name is Sam, and I am reading this sample to demonstrate the voice. — that is the canonical TTS demo phrase.

When to use OpenAI: GPT-4o Audio

Audiobooks

Long-form narration with consistent tone. Paste a chapter at a time, download as WAV or MP3, and stitch externally.

Podcast intros

Short opening bumpers and ad-reads. Adjust speed for energy, format-switch to MP3 for smaller files.

IVR + voicemail

Phone-system prompts. Studio-quality output without a booking, recording, or NDAs with voice talent.

Accessibility

Add audio alongside written content for low-vision and dyslexic readers. Drop-in on any page.

Sample phrases

"Welcome to the show, today we are exploring the future of AI."
"Your package has arrived. Please retrieve it from the front desk."
"Once upon a time, in a quiet village far away, lived a curious child."
"Press one for sales, two for support, or stay on the line for an agent."
"Breaking news: scientists have discovered a new species of deep-sea fish."
"Thank you for choosing us. We appreciate your business and look forward to serving you again."

Pricing

Premium TTS. Cost scales with character count — typically ~30 tokens per character. $1 buys 750,000 tokens; a $5 token pack covers tens of thousands of characters. Free signups get 10,000 tokens to try.

Full model reference → · See all TTS voices → · Compare 2 voices side-by-side →

Advanced options
Result
Tokens running low. Get More Tokens
Want better results? Premium models (GPT-5, Claude, Gemini) deliver higher quality. View Plans

❤️ Love Free.ai? Tell your friends!

Sign up to get a referral link and earn 25,000 tokens per friend.

Want more? Sign up free for 5K tokens/day + 10K bonus
Sign Up Free

Processing your request...

OpenAI: GPT-4o Audio is an AI model by OpenAI on Free.ai. It supports up to 128,000 tokens of context. Costs approximately 4,781 tokens per message. Try Op…

How to Use AI Voice — OpenAI: GPT-4o Audio

1
Enter your input

Type text, upload a file, or describe what you want. No account needed.

2
Click generate

Our AI processes your request in seconds using the best open-source models.

3
Download & share

Download, copy, or share your result. Free for personal and commercial use.

Use this tool via API

Automate this tool from your own code. OpenAI-compatible REST endpoint, Bearer-token auth, no extra SDK required. Token costs match the web interface.

API Documentation Get API Key 
curl -X POST https://api.free.ai/v1/tts/ \
  -H "Authorization: Bearer sk-free-..." \
  -H "Content-Type: application/json" \
  -d '{"text": "Hello from Free.ai", "voice": "af_heart", "model": "kokoro"}'

Related Free AI Tools

Voice Cloning
Voice Changer
AI Narrator
AI Dubbing
AI Voice Chat
Voice Recorder
Voice from Text
Celebrity Voice Generator

AI Voice — OpenAI: GPT-4o Audio — FAQ

OpenAI: GPT-4o Audio supports a wide range of languages. The exact list depends on the engine; the form on this page accepts any text and the engine will render in its supported languages. See /voice/ for the full multi-engine picker if you need a specific language.

Most engines render neutral-American English by default and a region-appropriate accent for non-English languages. Premium engines may expose accent variants — paste a sample to compare.

SSML support varies by engine. Pause, prosody, and emphasis tags are honored on most premium engines and on a few self-hosted ones. Plain text always works — no markup required.

Streaming TTS is available on premium engines via the /v1/tts/ API endpoint with stream=true. The web UI on this page returns the full clip once rendering finishes.

OpenAI: GPT-4o Audio is a premium TTS engine. Cost scales with character count — typically ~30 tokens per character. $1 buys 750,000 tokens, so a $5 pack covers tens of thousands of characters.

Up to 5,000 characters per request on the web UI. For longer pieces (audiobooks, full chapters), use /voice/audiobook/ which chunks and stitches automatically, or call the API in a loop.

Yes — POST a list of strings to /v1/tts/batch/, or use the workspace UI at /workspace/ to chain TTS into a longer pipeline (e.g., translate → speak → stitch).

Yes — POST text to /v1/tts/ with model="OpenAI: GPT-4o Audio" (or the slug on this page). Returns WAV or MP3. See /api/ for full reference + SDK snippets.

This page is text-to-speech, not voice cloning — the voice is the engine's default. For voice cloning (uploading a reference audio), see /voice/clone/, which requires you to either own the voice rights or have explicit written consent.

Self-hosted engines run on Free.ai-owned GPUs; nothing leaves our servers. Premium engines pass text to upstream model providers under our DPA. We do not train on your inputs and do not sell data.

Yes — Free.ai grants commercial use of generated audio. The engine's underlying license (Apache 2.0, MIT, or vendor terms) is shown above and on the model reference page; in practice this means voiceovers, ads, podcasts, and apps are all in-scope.

Yes — failed jobs auto-refund to the source (daily pool or paid tokens). If a refund does not show up the same day, email contact@free.ai.

Sign up free for 10,000 tokens

Create Free Account

No credit card required

How would you rate this tool?

4.3/5 from 3 ratings

Love Free.ai? Tell your friends!