Realtime TTS-2 Flash

API model ID: inworld-tts-2-flash
Access: Native synthesis API; account plan and concurrency limits apply.
Regions: General API region not pinned by these contracts. EU and India residency are enterprise offerings, not assumed for every request.
API endpoint URL: https://api.inworld.ai/tts/v1/voiceSource for API endpoint URL (opens in a new tab)
Streaming: Not supportedSource for Streaming (opens in a new tab)
Maximum prompt characters: 2,000 UTF-16 code unitsSource for Maximum prompt characters (opens in a new tab)
Request mode: Single JSON object with Base64 audioSource for Request mode (opens in a new tab)
Request quotas: TTS generation concurrency by plan: 5 / 10 / 50 / 150 / 500. WebSocket connections: 50 / 100 / 500 / 1,500 / 5,000; enterprise customSource for Request quotas (opens in a new tab)

Prices retain their published currencies and billing units below.

Published billing units · original currency · observed 13 Oct 2026
Category	Usage	Rate	Unit
Speech synthesis	Speech synthesis · On-Demand¹	$15.00	1M characters
Speech synthesis	Speech synthesis · Creator²	$10.00	1M characters
Subscription	Plan fee · Creator³	$25.00	month
Speech synthesis	Speech synthesis · Builder⁴	$9.00	1M characters
Subscription	Plan fee · Builder⁵	$100.00	month
Speech synthesis	Speech synthesis · Developer⁶	$8.00	1M characters
Subscription	Plan fee · Developer⁷	$300.00	month
Speech synthesis	Speech synthesis · Growth⁸	$7.00	1M characters
Subscription	Plan fee · Growth⁹	$1,500.00	month

Rate conditions

On-Demand plan: pay as you go after included trial credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Creator plan costs $25/month and includes $25 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $25 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Builder plan costs $100/month and includes $100 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $100 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Developer plan costs $300/month and includes $300 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $300 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Growth plan costs $1500/month and includes $1500 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $1500 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.

Data & enterprise terms

Inworld terms exclude nonpublic inputs/outputs from general model training, with feedback and trust/safety exceptions. ZDR is configurable and has product-specific exceptions; it is not a universal default. Pricing lists a Growth add-on, while the ZDR guide limits self-serve controls to Enterprise/Enterprise Trial. Confirm the actual workspace setting and contract. Clone samples and voice-design creation inputs are retained.

Inworld API

API model ID: inworld-tts-2-flash
Access: Native synthesis API; account plan and concurrency limits apply.
Regions: General API region not pinned by these contracts. EU and India residency are enterprise offerings, not assumed for every request.
API endpoint URL: https://api.inworld.ai/tts/v1/voice:streamSource for API endpoint URL (opens in a new tab)
Streaming: SupportedSource for Streaming (opens in a new tab)
Maximum prompt characters: 4,000 UTF-16 code unitsSource for Maximum prompt characters (opens in a new tab)
Request mode: Streaming JSON results with Base64 audio chunksSource for Request mode (opens in a new tab)
Request quotas: TTS generation concurrency by plan: 5 / 10 / 50 / 150 / 500. WebSocket connections: 50 / 100 / 500 / 1,500 / 5,000; enterprise customSource for Request quotas (opens in a new tab)

Prices retain their published currencies and billing units below.

Published billing units · original currency · observed 13 Oct 2026
Category	Usage	Rate	Unit
Speech synthesis	Speech synthesis · On-Demand¹	$15.00	1M characters
Speech synthesis	Speech synthesis · Creator²	$10.00	1M characters
Subscription	Plan fee · Creator³	$25.00	month
Speech synthesis	Speech synthesis · Builder⁴	$9.00	1M characters
Subscription	Plan fee · Builder⁵	$100.00	month
Speech synthesis	Speech synthesis · Developer⁶	$8.00	1M characters
Subscription	Plan fee · Developer⁷	$300.00	month
Speech synthesis	Speech synthesis · Growth⁸	$7.00	1M characters
Subscription	Plan fee · Growth⁹	$1,500.00	month

Rate conditions

On-Demand plan: pay as you go after included trial credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Creator plan costs $25/month and includes $25 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $25 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Builder plan costs $100/month and includes $100 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $100 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Developer plan costs $300/month and includes $300 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $300 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Growth plan costs $1500/month and includes $1500 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $1500 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.

Data & enterprise terms

Inworld API

API model ID: inworld-tts-2-flash
Access: Native synthesis API; account plan and concurrency limits apply.
Regions: General API region not pinned by these contracts. EU and India residency are enterprise offerings, not assumed for every request.
API endpoint URL: wss://api.inworld.ai/tts/v1/voice:streamBidirectionalSource for API endpoint URL (opens in a new tab)
Streaming: SupportedSource for Streaming (opens in a new tab)
Maximum prompt characters: 2,000 UTF-16 code units per sendText messageSource for Maximum prompt characters (opens in a new tab)
Request mode: Bidirectional text/audio contexts; explicit flush and close; SENTENCE_BOUNDARY automatic segmentation is PreviewSource for Request mode (opens in a new tab)
Request quotas: TTS generation concurrency by plan: 5 / 10 / 50 / 150 / 500. WebSocket connections: 50 / 100 / 500 / 1,500 / 5,000; enterprise customSource for Request quotas (opens in a new tab)
Session duration: Session closes after ten minutes of inactivity across contextsSource for Session duration (opens in a new tab)

Prices retain their published currencies and billing units below.

Published billing units · original currency · observed 13 Oct 2026
Category	Usage	Rate	Unit
Speech synthesis	Speech synthesis · On-Demand¹	$15.00	1M characters
Speech synthesis	Speech synthesis · Creator²	$10.00	1M characters
Subscription	Plan fee · Creator³	$25.00	month
Speech synthesis	Speech synthesis · Builder⁴	$9.00	1M characters
Subscription	Plan fee · Builder⁵	$100.00	month
Speech synthesis	Speech synthesis · Developer⁶	$8.00	1M characters
Subscription	Plan fee · Developer⁷	$300.00	month
Speech synthesis	Speech synthesis · Growth⁸	$7.00	1M characters
Subscription	Plan fee · Growth⁹	$1,500.00	month

Rate conditions

On-Demand plan: pay as you go after included trial credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Creator plan costs $25/month and includes $25 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $25 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Builder plan costs $100/month and includes $100 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $100 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Developer plan costs $300/month and includes $300 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $300 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Growth plan costs $1500/month and includes $1500 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $1500 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.

Data & enterprise terms

Inworld API

API model ID: inworld-tts-2-flash
Access: Native synthesis API; account plan and concurrency limits apply.
Regions: General API region not pinned by these contracts. EU and India residency are enterprise offerings, not assumed for every request.
API endpoint URL: https://api.inworld.ai/v1/audio/speechSource for API endpoint URL (opens in a new tab)
Streaming: SupportedSource for Streaming (opens in a new tab)
Maximum prompt characters: 4,000 charactersSource for Maximum prompt characters (opens in a new tab)
Request mode: Raw audio bytes or Server-Sent EventsSource for Request mode (opens in a new tab)
Request quotas: TTS generation concurrency by plan: 5 / 10 / 50 / 150 / 500. WebSocket connections: 50 / 100 / 500 / 1,500 / 5,000; enterprise customSource for Request quotas (opens in a new tab)
Output formats: mp3, opus, flac, wav, pcmSource for Output formats (opens in a new tab)
Audio sample rates: MP3/Opus/FLAC/WAV: 48 kHz mono; raw PCM16: 24 kHz monoSource for Audio sample rates (opens in a new tab)
Authentication: Bearer API key; other native TTS routes use Basic credentialsSource for Authentication (opens in a new tab)

Prices retain their published currencies and billing units below.

Published billing units · original currency · observed 13 Oct 2026
Category	Usage	Rate	Unit
Speech synthesis	Speech synthesis · On-Demand¹	$15.00	1M characters
Speech synthesis	Speech synthesis · Creator²	$10.00	1M characters
Subscription	Plan fee · Creator³	$25.00	month
Speech synthesis	Speech synthesis · Builder⁴	$9.00	1M characters
Subscription	Plan fee · Builder⁵	$100.00	month
Speech synthesis	Speech synthesis · Developer⁶	$8.00	1M characters
Subscription	Plan fee · Developer⁷	$300.00	month
Speech synthesis	Speech synthesis · Growth⁸	$7.00	1M characters
Subscription	Plan fee · Growth⁹	$1,500.00	month

Rate conditions

On-Demand plan: pay as you go after included trial credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Creator plan costs $25/month and includes $25 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $25 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Builder plan costs $100/month and includes $100 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $100 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Developer plan costs $300/month and includes $300 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $300 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.
Growth plan costs $1500/month and includes $1500 in shared product credits. Usage consumes credits at this plan rate; subscription fee is not an additional charge per request. Monthly credits roll over for up to three months under plan conditions; purchased top-ups expire after one year. No batch discount applied. TTS native usage counts UTF-16 code units; these are not LLM tokens. Taxes, custom enterprise terms and optional add-ons are separate.
Monthly subscription includes $1500 shared credits consumed at the plan’s unit rates. Annual subscriptions and custom agreements are separate. Do not add this full fee to each synthesis.

Data & enterprise terms

LiveKit Inference

API model ID: inworld/inworld-tts-2-flash
Access: Listed in LiveKit Inference; no separate Inworld key required. Host plan, default voice support and account limits apply.
Regions: Global. The model row does not list a dedicated EU endpoint.
Languages: View all 94 entries
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Source for Languages (opens in a new tab)
Streaming: SupportedSource for Streaming (opens in a new tab)

Prices retain their published currencies and billing units below.

Published billing units · original currency · observed 13 Oct 2026
Category	Usage	Rate	Unit
Speech synthesis	Speech synthesis · Build / Ship¹	$15.00	1M characters
Speech synthesis	Speech synthesis · Scale¹	$9.00	1M characters

Rate conditions

Published LiveKit Inference rate; plan fees, included credits, default-voice compatibility and enterprise terms are separate.

Data & enterprise terms

LiveKit documents zero retention for inference content by default, including underlying providers. Optional observability and custom-voice storage have separate handling.