ElevenLabs Eleven V4 & V4 Turbo vs Union Alpha (Stealth)
A direct, empirical evaluation of ElevenLabs Eleven V4 & V4 Turbo (ElevenLabs) against Union Alpha (Stealth) (OpenRouter & OpenCode).
ElevenLabs Eleven V4 & V4 Turbo
Developed by ElevenLabs · Frontier Neural Acoustic Waveform Transformer parameters
Real-time conversational voice agents (<80ms latency), 90-language studio voice cloning, granular emotional tags (<whisper>, <shout>), and 48kHz production voice synthesis.
Union Alpha (Stealth)
Developed by OpenRouter & OpenCode · Multi-Model Ensemble Mixture parameters
Terminal coding agents, pull-request synthesis, multi-model consensus verification, and zero-cost autonomous refactoring.
| Metric | ElevenLabs Eleven V4 & V4 Turbo | Union Alpha (Stealth) |
|---|---|---|
| SWE-bench Verified | 0% | 74.2% |
| MMLU-Pro | 0% | 89.8% |
| MATH-500 | 0% | 95.4% |
| Context Window | 128,000 characters | 256,000 tokens |
| Input Pricing (per 1M) | $0.15 | $0.00 |
| Output Pricing (per 1M) | $0.30 | $0.00 |