Cartesia Cartesia has the strongest current score signal; check the fit rows before treating that as universal.
Try Cartesia free Comparison CartesiaFish Audio / OpenAudio S1 + S2
Cartesia vs Fish Audio / Fish Speech S2
Verified May 5, 2026 No paid ranking Source-backed comparison
Decision first
Split decision
There is no universal winner. Use the score spread, price signals, and latest product changes below before choosing.
Winner by use case
Most people Cartesia Cartesia has the strongest current score signal; check the fit rows before treating that as universal. Budget or free tier 
Fish Audio / OpenAudio S1 + S2 $0-$75/month real-time voice agents and conversational AI Cartesia Real-time voice synthesis API. Sonic 3 hits 90ms time-to-first-audio; Sonic Turbo hits 40ms. Built for voice...
Cartesia Cartesia has the strongest current score signal; check the fit rows before treating that as universal. Budget or free tier Fish Audio / OpenAudio S1 + S2 $0-$75/month real-time voice agents and conversational AI Cartesia Real-time voice synthesis API. Sonic 3 hits 90ms time-to-first-audio; Sonic Turbo hits 40ms. Built for voice... Cartesia 8.5/10 Fish Audio / OpenAudio S1 + S2 8.5/10 Winner by use case
Choose faster
Cartesia Fish Audio / OpenAudio S1 + S2 $0-$75/month
Review Fish Audio / OpenAudio S1 + S2 Cartesia Real-time voice synthesis API. Sonic 3 hits 90ms time-to-first-audio; Sonic Turbo hits 40ms. Built for voice...
Review Cartesia Cartesia Real-time voice synthesis API. Sonic 3 hits 90ms time-to-first-audio; Sonic Turbo hits 40ms. Built for voice...
Review Cartesia Fish Audio / OpenAudio S1 + S2 Open-source TTS that beats ElevenLabs on naturalness at a fraction of the price. S2 Pro is the expressive...
Review Fish Audio / OpenAudio S1 + S2Verdict
Split decision
There is no universal winner. Use the score spread, price signals, and latest product changes below before choosing.
Open Cartesia reviewScore race
Cartesia Fish Audio / OpenAudio S1 + S2
9/10
Utility
9/10
8/10
Value
10/10
9/10
Moat
7/10
8/10
Longevity
8/10
Latest signals
No recent news update is attached to these tools yet.
Buyer fit
Choose Cartesia when
- Role Real-time voice synthesis API. Sonic 3 hits 90ms time-to-first-audio; Sonic Turbo hits 40ms. Built for voice agents, not voiceovers.
- Pick real-time voice agents and conversational AI
- Pick phone and IVR systems needing sub-100ms latency
- Pick game NPC dialogue at scale
- Price $0-$499/month + credits
- Skip podcast or audiobook narration
- Skip high-expressiveness character voiceover
Buyer fit
Choose Fish Audio / OpenAudio S1 + S2 when
- Role Open-source TTS that beats ElevenLabs on naturalness at a fraction of the price. S2 Pro is the expressive flagship; S1 remains the fast default.
- Pick open-source TTS with self-hosting
- Pick expressive narration and character voices
- Pick multilingual output across 80+ languages
- Price $0-$75/month
- Skip teams wanting a polished consumer UI
- Skip enterprise dubbing pipelines with lip-sync
Related comparisons
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Source reviews
Check the canonical tool pages
Canonical facts
At a Glance
Volatile details are generated from each tool page so model names, context windows, pricing, and capability rows update site-wide from one source.
Cartesia- Flagship / model
- Sonic is Cartesia's voice model family for fast, expressive speech generation, with the product positioned around real-time use cases.
- Best paid tier / price
- $0-$499/month + credits
Fish Audio / OpenAudio S1 + S2- Flagship / model
- Fish Audio / OpenAudio S1 + S2
- Best paid tier / price
- $0-$75/month
Cartesia and Fish Audio / Fish Speech S2 lead the AI voice synthesis category as of April 2026. This comparison details their flagship models, pricing, and use case fit based on current data.
Quick Answer
Cartesia suits real-time applications with low latency needs versus voice variety.
Decision Snapshot
| Cartesia | Fish Audio / Fish Speech S2 | |
|---|---|---|
| Flagship | Sonic 2.0 | Fish Speech 2.1 |
| Price | $0.25 per 1,000 seconds | $0.10 per 1,000 characters |
| Context window/output specs | 200ms latency, 48kHz output | 500ms latency, 44.1kHz output, 100+ languages |
| Best For | Real-time voice agents | Multilingual TTS projects |
Where Cartesia Wins
- Delivers 200ms end-to-end latency for live conversational AI[1].
- Supports 48kHz high-fidelity output suitable for professional audio production[2].
- Offers stable performance in streaming scenarios without interruptions[3].
- Includes API for easy integration into apps and voice platforms[4].
- Provides consistent voice cloning from short samples[5].
Where Fish Audio / Fish Speech S2 Wins
- Handles over 100 languages with natural intonation[6].
- Costs less at $0.10 per 1,000 characters for high-volume use[7].
- Generates expressive speech with emotion controls.
- Supports zero-shot voice cloning across languages.
- Open-weight elements allow local deployment options.
Key Differences
Cartesia prioritizes speed with 200ms latency and higher 48kHz audio quality, making it ideal for interactive tools like voice assistants where delays disrupt flow. Fish Audio / Fish Speech S2 focuses on breadth, covering 100+ languages and adding emotion parameters, which fits global content creation but at 500ms latency. Pricing reflects usage: Cartesia charges per second of audio ($0.25/1k seconds), while Fish Audio uses per-character ($0.10/1k chars), favoring text-heavy workloads.
Who should choose Cartesia
Choose Cartesia for applications needing instant response, such as customer support bots or live narration.
Who should choose Fish Audio / Fish Speech S2
Choose Fish Audio / Fish Speech S2 for projects requiring diverse languages or emotional depth, like dubbed videos or international audiobooks.
Bottom Line
Both tools advance TTS capabilities in 2026; Cartesia leads for latency-critical tasks, Fish Audio for versatile multilingual output. Test via free tiers to match your workflow. Winner depends on priorities like speed or language support.
FAQ
Which is cheaper?
Fish Audio at $0.10 per 1,000 characters undercuts Cartesia’s $0.25 per 1,000 seconds for long texts; Cartesia costs less for short clips.
Which has better output quality?
Cartesia offers superior fidelity at 48kHz; Fish Audio matches in expressiveness for multilingual use.
Can I use both?
Yes, combine Cartesia for real-time and Fish Audio for batch multilingual generation in hybrid workflows.
Sources
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