Speko is a voice AI benchmarking and optimization platform. It connects to 18+ voice AI providers and automatically tests 240+ STT, LLM, and TTS combinations against your specific language, use case, and cost constraints — returning ranked results in minutes.

Which voice AI providers does Speko support?

Speko supports 18+ providers including Deepgram, AssemblyAI, ElevenLabs, Cartesia, PlayHT, OpenAI, Gemini, Groq, Cerebras, Vapi, Retell, Bland AI, Hume AI, and more. New providers are added regularly.

How does Speko benchmark voice AI providers?

Speko runs STT, LLM, and TTS providers in combination against your specific inputs, measuring latency, accuracy, cost, and quality. Every benchmark number is cited with source URLs and verification dates. See our methodology at speko.ai/blog/methodology.

Which STT provider is most accurate for English?

Based on our March 2026 benchmarks, Deepgram Nova-3 and AssemblyAI Universal-3 Pro lead for English accuracy. Deepgram Nova-3 achieves 4.1% WER on clean audio; AssemblyAI Universal-3 Pro averages 5.9% WER across 26 diverse datasets. The best choice depends on your audio conditions and latency requirements.

What is the cheapest voice AI stack in 2026?

The lowest-cost production-ready stack is approximately $0.0095/minute, combining Deepgram Nova-3 ($0.0043/min) + Gemini 2.0 Flash ($0.0007/min) + Cartesia Sonic ($0.0045/min). See our full cost breakdown at speko.ai/blog/voice-ai-cost-2026.

How is Speko different from Vapi or Retell?

Vapi and Retell are voice agent platforms that lock you into their provider choices. Speko is provider-agnostic infrastructure that benchmarks all providers against your requirements and helps you choose and switch freely. Speko integrates with any platform including Vapi, Retell, and custom stacks.

ANSWERS

ElevenLabs vs Deepgram in 2026

Head-to-head comparison based on Speko benchmark data. STT accuracy, TTS quality, latency, pricing, and language support.

Last updated: April 2026

According to Speko's 2026 benchmarks, Deepgram Nova-3 is better for real-time STT (sub-300ms, $0.0043/min, 5.9% WER streaming), while ElevenLabs leads on TTS voice quality (MOS 4.5/5 per provider data) and voice cloning. They serve different strengths — many production systems use both together. Speko benchmarks them side by side with your actual data.

ElevenLabs and Deepgram are not direct competitors — they each lead in different categories. This comparison breaks down where each provider wins and when you should use one, the other, or both.

Speech-to-Text Comparison

STT capabilities compared. Data from Speko benchmarks, March 2026.

Metric

Deepgram Nova-3

ElevenLabs Scribe v2

WER (streaming)

5.9%

2.3%

Streaming latency

< 300ms

~800ms

Cost per minute

$0.0043

$0.0050

Languages supported

Speaker diarization

Yes

Real-time streaming

Yes (WebSocket)

Batch only

Best for

Voice agents, real-time

Batch transcription

Text-to-Speech Comparison

TTS capabilities compared. MOS scores from provider-reported data and third-party evaluations.

Metric

Deepgram Aura

ElevenLabs Turbo v3

Voice quality (MOS)

3.9/5

4.5/5

Time-to-first-byte

~200ms

250-350ms

Cost per minute

$0.0035

$0.0180

Voice cloning

Yes (instant + pro)

Emotion control

Limited

Advanced

Languages

Best for

Cost-sensitive, IVR

Premium, customer-facing

When to Choose Each Provider

Choose Deepgram When...

Building real-time voice agents — Sub-300ms STT streaming is essential for natural conversation. No other provider matches Deepgram's speed-to-accuracy ratio.
Cost is a primary concern — Deepgram is cheaper on both STT ($0.0043/min) and TTS ($0.0035/min). At scale, the savings are significant.
High-volume transcription — Call centers and media transcription benefit from Deepgram's speed and affordable batch pricing.

Choose ElevenLabs When...

Voice quality is the top priority — MOS 4.5/5 with emotional range, prosody control, and the most natural-sounding voices in the market.
You need voice cloning — ElevenLabs offers instant cloning (30s of audio) and professional cloning (30min). Deepgram does not offer cloning.
Batch transcription accuracy — Scribe v2 at 2.3% WER is the most accurate STT when latency is not a constraint.

Use Both Together When...

Building premium voice agents — Deepgram Nova-3 for STT (fastest) + ElevenLabs Turbo v3 for TTS (best quality). This is a common production pattern.
Different quality tiers — Use Deepgram Aura for IVR/low-priority and ElevenLabs for customer-facing interactions. Route based on caller value.

Why Compare with Speko?

Static comparisons go stale. Speko benchmarks ElevenLabs, Deepgram, and 14+ other providers against your actual data in real-time.

Live Provider Benchmarking

Run ElevenLabs and Deepgram side by side with your audio and text. Get real latency, accuracy, and cost numbers, not generic benchmarks.

Mix and Match Providers

Test Deepgram STT + ElevenLabs TTS and every other combination. Find the optimal stack for your specific use case.

Switch Without Code Changes

Speko's unified API lets you swap providers instantly. Start with one, switch to another as your needs evolve.

Frequently Asked Questions

Is ElevenLabs or Deepgram better for speech-to-text?▾

For real-time STT, Deepgram Nova-3 is better: sub-300ms latency at $0.0043/min with 5.9% WER (streaming). ElevenLabs Scribe v2 wins on raw accuracy (2.3% WER) but has higher latency (~800ms) and costs more ($0.0050/min). Choose Deepgram for voice agents and ElevenLabs for batch transcription where accuracy outweighs speed.

Is ElevenLabs or Deepgram better for text-to-speech?▾

ElevenLabs Turbo v3 produces higher-quality voices (MOS 4.5/5 per provider-reported data) with advanced features like voice cloning and emotional control. Deepgram Aura is 5x cheaper ($0.0035/min vs $0.0180/min) with faster latency (~200ms vs 250-350ms TTFB). For premium customer-facing applications, ElevenLabs is better. For cost-sensitive high-volume deployments, Deepgram wins.

Which is cheaper, ElevenLabs or Deepgram?▾

Deepgram is significantly cheaper across both STT and TTS. For STT: Deepgram Nova-3 costs $0.0043/min vs ElevenLabs Scribe at $0.0050/min. For TTS: Deepgram Aura costs $0.0035/min vs ElevenLabs at $0.0180/min. At 10,000 minutes/month, Deepgram saves $145/month on TTS alone.

Can I use both ElevenLabs and Deepgram together?▾

Yes, and many production voice agents do exactly this. A common high-performance stack is Deepgram Nova-3 for STT (fastest) + ElevenLabs Turbo v3 for TTS (best quality). Speko's unified API lets you mix and match providers and switch between them without changing your integration code.

Which supports more languages, ElevenLabs or Deepgram?▾

ElevenLabs supports 32 languages for TTS with high-quality voices in each. Deepgram Nova-3 supports 36 languages for STT. For multilingual voice agents, you can combine both: Deepgram for transcription and ElevenLabs for speech synthesis.

How does Speko help compare ElevenLabs and Deepgram?▾

Speko benchmarks both providers (and 14+ others) against your specific audio, text, and language requirements. Instead of reading comparison articles, you can run actual API calls with your data and see real latency, accuracy, and cost numbers side by side. Speko also tests them in combination with LLMs for full voice agent stack comparisons.

Methodology

STT data from Speko's curated benchmarks using standardized audio datasets (clean, noisy, accented). TTS MOS scores from provider-reported data and third-party evaluations. Pricing from published rate cards. Last verified: March 2026.

Read our full testing methodology Deepgram vs AssemblyAI: another head-to-head benchmark ElevenLabs vs Cartesia: TTS-focused benchmark

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