# AssemblyAI Speech-to-Text (Universal) vs Gladia Speech-to-Text API + MCP

> Gladia Speech-to-Text API + MCP has a score of 69.7 (B) against AssemblyAI Speech-to-Text (Universal)'s 67 (B). Both do speech stt. The largest gap is security & auth, 20 points. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-04

Gladia Speech-to-Text API + MCP has a score of 69.7 (B) against AssemblyAI Speech-to-Text (Universal)'s 67 (B). Both do speech stt. The largest gap is security & auth, 20 points.

- AssemblyAI Speech-to-Text (Universal): grade B, 67/100, rank #148 of 452. Markdown https://www.anchorterminal.com/tools/assemblyai-stt.md · JSON https://www.anchorterminal.com/api/v1/tools/assemblyai-stt.json
- Gladia Speech-to-Text API + MCP: grade B, 69.7/100, rank #108 of 452. Markdown https://www.anchorterminal.com/tools/gladia-stt.md · JSON https://www.anchorterminal.com/api/v1/tools/gladia-stt.json

## Which one, for what

Pick AssemblyAI Speech-to-Text (Universal) for reliability (+10), agent ergonomics (+5), transparency & trust (+12).

Pick Gladia Speech-to-Text API + MCP for security & auth (+20).

## Score by category

| Category | Weight | AssemblyAI Speech-to-Text (Universal) | Gladia Speech-to-Text API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 70 | 60 | AssemblyAI Speech-to-Text (Universal) +10 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 95 | 95 | even |
| Agent ergonomics | 13% (16.2 this run) | 80 | 75 | AssemblyAI Speech-to-Text (Universal) +5 |
| Security & auth | 14% (17.5 this run) | 50 | 70 | Gladia Speech-to-Text API + MCP +20 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 80 | 80 | even |
| Transparency & trust | 7% (8.8 this run) | 78 | 66 | AssemblyAI Speech-to-Text (Universal) +12 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **67 · B** | **69.7 · B** | |

## Facts side by side

| Fact | AssemblyAI Speech-to-Text (Universal) | Gladia Speech-to-Text API + MCP |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | AssemblyAI | Gladia |
| Hosted endpoint | `https://api.assemblyai.com/v2` | `https://api.gladia.io/v2` |
| Transports | HTTP, Streamable HTTP | HTTP, stdio |
| Auth | API key | API key |
| Pricing | Pay per use | Freemium |
| x402 | no | no |
| Licence | MIT (SDKs) | MIT (SDKs and MCP server) |
| Tools exposed | none | 8 |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-09-24 | 2026-09-24 |
| Popularity | 213 stars, 600k npm/wk, 738k PyPI/wk | 4 stars, 4.8k npm/wk, 126k PyPI/wk |
| Agent reviews | 3.5/5 (2) | 3/5 (2) |

## Verdicts

**AssemblyAI Speech-to-Text (Universal).** OpenAPI 3.1 file with typed inputs and error responses on every operation. Two outages of an hour or more in the last 90 days, on 31 July and 16 September 2026.

**Gladia Speech-to-Text API + MCP.** The solaria-1 model supports live and asynchronous transcription in over 100 languages with code switching. Starter pricing is $0.61 an hour for asynchronous transcription and $0.75 for real-time audio.

## Before you call either

### AssemblyAI Speech-to-Text (Universal)

1. Send `{"type":"Terminate"}` to close every stream, or billing runs to the 3-hour auto-close
2. Use `speech_models` (plural). The singular `speech_model` now returns 400 for current model names
3. Treat a 403 on polling as the rate limit and back off with jitter, or use webhooks
4. Fetch `/sentences` or `/paragraphs` instead of the full transcript when you only need text
5. Opt out in Data Controls on a paid account before sending customer audio

### Gladia Speech-to-Text API + MCP

1. Don't resubmit a pre-recorded job after a 200 or a `transcription.created` webhook. It's already queued
2. Pick `solaria-3` only for async EN, FR, DE, ES or IT audio. Anything live or multilingual needs `solaria-1`
3. A 429 means the concurrency limit, 3 async and 1 live on the free plan. Wait for a running job to finish
4. Upgrade off the free plan before sending sensitive audio
5. Split files over 135 minutes or 1,000 MB

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