Grok Speech (STT + TTS APIs) vs Perplexity Comet

Which one should you pick? Here's the full breakdown.

Grok Speech (STT + TTS APIs)

8.1/10

xAI's standalone voice APIs -- launched 2026-04-17. Built on the stack that powers Grok Voice, Tesla vehicles, and Starlink customer support. $0.10/hr STT batch, $4.20 per 1M characters TTS, 25+ languages, word-level timestamps + speaker diarization

Our Pick

Perplexity Comet

8.4/10

Perplexity's agentic AI browser -- FREE on all platforms as of 2026-03-18 (previously $200/mo Max-only). iOS, Android, Windows, Mac. Browses the web, executes multi-step tasks, and summarizes pages in-line. Comet Plus ($5/mo) adds premium publisher content

Category	Grok Speech (STT + TTS APIs)	Perplexity Comet
Ease of Use	7.0	8.0
Output Quality	8.5	8.0
Value	9.0	9.5
Features	8.0	8.0
Overall	8.1	8.4

Pricing Comparison

Feature	Grok Speech (STT + TTS APIs)	Perplexity Comet
Free Tier	No	Yes
Starting Price	$0.10	$0

Which Should You Pick?

Pick Grok Speech (STT + TTS APIs) if...

Developers building voice agents, real-time transcription tools, accessibility features, or high-volume TTS workloads where the cost per hour of audio actually matters at scale. Strong fit for phone-call and meeting transcription use cases where xAI's published WER advantage (5.0% on phone-call entities vs. ElevenLabs 12.0%) compounds quickly.

Visit Grok Speech (STT + TTS APIs)

Pick Perplexity Comet if...

✓Easier to use (8 vs 7)
✓Has a free tier

Users who already use Perplexity for search and want an agent browser that can complete multi-step tasks (booking, research, shopping, document summarization) across tabs. Also a strong introduction to the AI-browser category for anyone curious but unwilling to pay $200/mo for a preview -- the 2026-03-18 free rollout makes evaluation risk-free.

Visit Perplexity Comet

Our Verdict

Perplexity Comet edges out Grok Speech (STT + TTS APIs) with a 8.4 vs 8.1 overall score. Both are solid picks, but Perplexity Comet has the advantage in value.