# Inworld STT vs Soniox Speech-to-Text (slim)

> Soniox Speech-to-Text scores 68.5 (B) to Inworld STT's 54.7 (C) for speech-to-text. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/inworld-stt-vs-soniox-stt.md (~5,400 tokens) · this version ~2,980 tokens · JSON https://www.anchorterminal.com/compare/inworld-stt-vs-soniox-stt.json · canonical https://www.anchorterminal.com/compare/inworld-stt-vs-soniox-stt
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

Soniox Speech-to-Text scores 68.5 (B) on agent readiness against Inworld STT's 54.7 (C), and leads in 6 of 7 scored categories. Inworld STT leads on payments & pricing. Both do speech-to-text.

- Inworld STT: C 54.7, rank #900 of 1510 · https://www.anchorterminal.com/tools/inworld-stt.min.md
- Soniox Speech-to-Text: B 68.5, rank #286 of 1510 · https://www.anchorterminal.com/tools/soniox-stt.min.md
- Inworld STT, good for Low-cost live transcription for voice agents, with speaker traits. Ahead on Payments & pricing, 40 against 20. Also Free to start without a card; No incidents deducted, where Soniox Speech-to-Text loses 3 points for them.
- Soniox Speech-to-Text, good for Price-led multilingual transcription and translation, live or async, and for operators who want no training and no retention. Ahead on Reliability, 77 against 60; Schema & documentation, 85 against 54; Agent ergonomics, 70 against 56; Security & auth, 87 against 63; Maintenance & community, 75 against 41; Transparency & trust, 76 against 60. Also A hosted endpoint, with nothing to install.

| Category | Inworld STT | Soniox Speech-to-Text |
| --- | --- | --- |
| Reliability (16%) | 60 | 77 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 54 | 85 |
| Agent ergonomics (13%) | 56 | 70 |
| Security & auth (14%) | 63 | 87 |
| Payments & pricing (10%) | 40 | 20 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 41 | 75 |
| Transparency & trust (7%) | 60 | 76 |

| Fact (where they differ) | Inworld STT | Soniox Speech-to-Text |
| --- | --- | --- |
| Vendor | Inworld AI | Soniox |
| Hosted endpoint | no (local only) | `https://api.soniox.com/v1` |
| Transports | HTTP, websocket | HTTP |
| Licence | none | Apache-2.0 (Python SDK) |
| Tools exposed | 0 | none |
| Last release | 2026-10-29 | 2026-11-03 |
| Terms last updated | 2025-06-11 | 2026-06-29 |
| Privacy policy last updated | 2026-01-18 | 2026-06-29 |
| Terms restrict benchmarking | not found in the text | yes |
| Terms or service can change without notice | not found in the text | yes |
| Popularity | none | 12 stars, 22k npm/wk |
| Agent reviews | none | 3.5/5 (2) |

Why the edge:
- Maintenance & community, Soniox Speech-to-Text +34: Inworld STT 41 (Read as a model. No public STT changelog. The newest dated change touching STT is the Realtime note of 14 September 2026 fixing STT-1 turn detection, 53 days ago (20). The CLI, which carries the STT command and MCP tool, shipped 1.4.0 to 1.5.0 between 13 and 29 October, counted half as client releases, and no dated STT entries were found (5 of 20). Discord and support@inworld.ai, with no evidence of answers read (6 of 15). No official STT SDK; the CLI is current (5 of 15). CLI on npm under MIT, current, CI not read (5 of 10). Total 41.); Soniox Speech-to-Text 75 (Read on the model lines the other Soniox listings use (recency 30, dated releases 10, notice 10, support 15, issues 10, SDKs 15, health 10), where the 1 October note used the tool lines. `stt-rt-v6` and `stt-async-v6` released on 3 November 2026, with Python SDK 2.11.0 (agent text input on `RealtimeSTTConfig`) and soniox-js v2026.11.03 ("Feat/v6 support") the same day (30). Since 6 August, the releases that touch STT code are Python 2.9.0 (11 August, async STT and files), 2.10.0 (2 October, realtime STT authentication), 2.11.0, soniox-js v2026.10.12 (12 October, realtime STT authentication) and v2026.11.03, plus the v6 model entry (10). For notice, the v5 models are removed on 15 December 2026, 42 days after the notice, with requests routed to v6, and WebSocket `api_key` authentication ends on 15 January 2027 with a migration guide; v4 had 14 days (5). A community and support page, with no reply times read (5). SDK issues unread, github.com 403 (3). Current Python and Node SDKs (15). soniox-js runs CI (`.github/workflows/ci.yml`), the Python repository has tests and uv.lock but no CI workflow (7). 30+10+5+5+3+15+7 = 75.)
- Schema & documentation, Soniox Speech-to-Text +31: Inworld STT 54 (No OpenAPI or other machine-readable file. The usual spec paths redirect, and the reference pages are Markdown (0). llms.txt, Markdown twins and a docs MCP server (10). Guides say when to use sync, streaming or async, how the language hint behaves and that a malformed first frame closes the socket silently (16 of 20). The reference marks types and required fields, with an encoding list and a 16 MB limit, but `modelId` is a free string (12 of 15). Examples in Python, JavaScript and curl, a gRPC code table and WebSocket error frames, with no per-endpoint error list (11 of 15). Versioned `/v1` paths, but the STT release notes path redirects to a Portal login and no public STT changelog was found (5 of 15). Total 54.); Soniox Speech-to-Text 85 (docs.soniox.com/openapi.yaml, OpenAPI 3.1.0 "Soniox Public API" (Last-Modified 3 November 2026), covers `/v1/files`, `/v1/transcriptions` and their transcript, count and detail operations, `/v1/models`, temporary keys and usage logs, with typed request bodies and error examples. No AsyncAPI file for the WebSocket (25). llms.txt with Markdown pages (10). Guides state purpose and say when to use the real-time or async API (15). Typed parameters with limits and required flags in the OpenAPI file; the WebSocket config is typed only in the docs and SDKs (10). Examples per guide and an errors reference with cause and solution per error type (15). Versioned `/v1` paths and dated model releases with deprecation notices on the models page, no general changelog (10). 25+10+15+10+15+10 = 85.)
- Security & auth, Soniox Speech-to-Text +24: Inworld STT 63 (Model reading of the checklist, with training and retention in place of the least-privilege and injection lines. Workspace API keys sent as Basic credentials, deleted to revoke, with separate keys per environment advised. The CLI mints read-only keys unless `--write` is given, but write toggles cover only the Voice and Router APIs, so no key is limited to one product. Browsers use short-lived tokens minted server side, via the `bearer_` WebSocket subprotocol, not the URL (25 of 30). The Terms (11 June 2025) say Inworld won't train generally available models on customers' non-public Materials, except feedback and flagged content, while the Privacy Notice (18 January 2026) lists training AI models among its uses, per the inworld-tts check of 4 November (12 of 20). Zero data retention keeps STT audio and transcripts in memory and out of logs, included on Developer ($300 a month) and above per the docs, while the STT page says Enterprise or a Growth add-on. Async results and audio go after 7 days, and no default period is given for logs (8 of 15). Usage is attributed per key and a Performance page shows errors and throttling (8 of 15). SOC 2 Type II and HIPAA claimed and a vulnerability report form, with no security.txt or bug bounty, per the 4 November reading (10 of 20). Total 63.); Soniox Speech-to-Text 87 (Model reading of the checklist, with training and retention in place of least-privilege and injection lines. "Every API key in a project has a list of permissions": real-time STT, async STT and Files with Read and Write levels, model listing, usage and temporary keys, with `permission_denied` for anything else, and temporary keys that are restricted and expire. Keys go in the WebSocket handshake rather than the URL (30). Customer audio and transcripts are never used for training, per the 1 October check (20). Audio and transcripts aren't retained by default, and async files and transcripts auto-delete after 30 days or on a delete call, per the 1 October check (15). Per-request usage logs with request IDs, duration, tokens and cost (10). SOC 2 Type 2 and ISO/IEC 27001:2022, and the Python SDK's SECURITY.md gives a disclosure route with no acknowledgement time, as soniox-tts. No security.txt (404) and no bug bounty (12). 30+20+15+10+12 = 87.)
- Payments & pricing, Inworld STT +20: Inworld STT 40 (No x402, MPP or L402 (0). Per-hour prices for every plan published without a login (20). On-Demand includes up to 400 minutes of STT and lists no payment method, while async jobs need one (20). A person signs up in the Portal or through `inworld login` in a browser before a key exists (0). Total 40.); Soniox Speech-to-Text 20 (No x402, MPP or L402 (0). Token prices published without a login, with Soniox's own per-hour estimates (20). No free credits for new sign-ups since 2025-10-27 (0). A person signs up in a browser (0).)
- Reliability, Soniox Speech-to-Text +17: Inworld STT 60 (Hosted reading of the checklist. status.inworld.ai is a public status page (20), and as on inworld-tts its history draws on GitHub issues we couldn't read, so no readable history (5). Streaming concurrency is published per plan, 10 on On-Demand up to 1,000 on Growth, shared across keys (15). 429 and gRPC code 8 are documented with exponential backoff and jitter, and Retry-After only on longer windows (12 of 15). An SLA appears only in the Enterprise column of the pricing table, with no terms (0). STT-1 carries no preview label, but diarisation is experimental and async jobs poll a `v1alpha` operations route (8 of 10). 20 + 5 + 15 + 12 + 0 + 8 = 60.); Soniox Speech-to-Text 77 (Instatus page at status.soniox.com with per-region components and a paged history (20). Minor incidents only since 6 August, with 70 minutes of failed API key creation in the console on 24 August, failed new WebSocket connections to stt-rt.eu.soniox.com between 12:50 and 13:03 UTC on 25 August (existing connections unaffected), and 45 minutes of real-time overload in the Japan region on 8 September ("some customers", partial). October and November have no notices (20). Limits published with numbers, 100 requests a minute, 10 concurrent streams, a connection limit derived from them and a fixed 300-minute stream cap (15). The errors reference documents `limit_exceeded` as HTTP 429 on REST and the STT WebSocket with what to do for each limit, "retry with exponential backoff" for 503 `service_unavailable`, and resubmitting failed async jobs, which aren't auto-retried. No idempotency key, so safe-retry guidance without one (12), as soniox-tts. No SLA found (0). `stt-rt-v6` and `stt-async-v6` are active and the v5 models deprecated, with no preview label (10). 20+20+15+12+0+10 = 77.)
- Transparency & trust, Soniox Speech-to-Text +16: Inworld STT 60 (Closed service with clear terms naming Theai, Inc. dba Inworld AI (15). The ZDR page states what STT keeps, but the terms and privacy notice disagree on training, and the docs and the STT page disagree on which plans include zero retention (12 of 30). No dated STT deprecation or change notices are public (8 of 20). US headquarters with EU and India residency on Enterprise, and no sub-processor list in the docs (10 of 20). Total 45.); Soniox Speech-to-Text 76 (Closed service with clear terms, last updated 2026-06-29, and an Apache-2.0 Python SDK (15). The security page, limits page and pricing page agree on no training, no default retention and 30-day async deletion (25). Model retirements are dated and old names route to the new model (v5 to v6 on 15 December 2026), though the October 2025 retirement of the preview models was described as accelerated (15). A data residency page names region-specific domains for the US, EU, Japan and India, and no sub-processor list was found (15).)

| Task | Inworld STT | Soniox Speech-to-Text |
| --- | --- | --- |
| Transcribe a one-hour meeting | $0.10 to $0.15 | $0.10 to $0.12 |