Grok Speech (STT + TTS APIs)
No free tier
- Speech to Text (batch)$0.10/per hour
- Speech to Text (streaming)$0.20/per hour
- Text to Speech$4.20/per 1M characters
Our pickGrok Speech (STT + TTS APIs)

Microsoft Agent 365
Tier-list head-to-head. Grok Speech (STT + TTS APIs) takes the A-tier slot — here's the breakdown.
Spec sheet
| Tier | A-tierwin | B-tier |
| Overall score | 8.1 / 10win | 7.5 / 10 |
| Free tier | No | No |
| Starting price | $0.10 | $15 |
| Best for | Developers building voice agents, real-time transcription tools, accessibility features, or high-volume TTS… | Enterprise IT and security teams running mixed-AI environments who need a single pane of glass over local a… |
| Last reviewed | 2026-04-18 | 2026-05-01 |
Head-to-head
Rated 1-10 on the same rubric across all 130 tools we cover.
What you'll pay
Look past the headline number -- entry-tier limits drive most cost surprises.
No free tier
No free tier
The decision
Use-case anchors and category strengths, side by side.
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)Enterprise IT and security teams running mixed-AI environments who need a single pane of glass over local agents (OpenClaw, Copilot CLI, Claude Code), Copilot Studio agents, and cloud agents in AWS Bedrock / Google Cloud / Azure. Especially valuable for orgs already on Microsoft 365 E5/E7 where the bundled tier removes the per-seat math.
Visit Microsoft Agent 365Bottom line
Grok Speech (STT + TTS APIs) edges out Microsoft Agent 365 by 0.6 points (8.1 vs 7.5) -- a A-tier vs B-tier split that's narrow but real. Not a blowout; both belong on a shortlist. The score gap shows up most clearly in the categories that matter for Grok Speech (STT + TTS APIs)'s strengths, so if those categories are your priority, the lead translates.
Neither tool offers a free tier. Grok Speech (STT + TTS APIs) starts at $0.10, Microsoft Agent 365 at $15. Plan to budget for whichever you pick. The cheap tier usually caps out faster than buyers expect, so look at what the entry plan actually includes -- both vendors have raised list prices in 2026 and the limits are where most of the cost surprise lives.
By use case: pick Grok Speech (STT + TTS APIs) when 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. Pick Microsoft Agent 365 when enterprise it and security teams running mixed-ai environments who need a single pane of glass over local agents (openclaw, copilot cli, claude code), copilot studio agents, and cloud agents in aws bedrock / google cloud / azure. The two tools aren't fighting for the same person -- they're aiming at adjacent jobs that occasionally overlap. If you're squarely in Grok Speech (STT + TTS APIs)'s lane, the tier-list ranking and the use-case fit point the same direction; if you're in Microsoft Agent 365's lane, the score gap matters less than the fit.
Bottom line: Grok Speech (STT + TTS APIs) is the safer default for most readers, but Microsoft Agent 365 is competitive enough that the tie-breaker is your specific workload, not the spec sheet.
Keep digging
Full Grok Speech (STT + TTS APIs) review
Tier A · 8.1/10
Full Microsoft Agent 365 review
Tier B · 7.5/10
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Built from our daily AI-tool sweep, last touched May 1, 2026. Honest tier-list reviews — no affiliate-link pieces disguised as advice. See the rubric or how we review.