# Cartesia Ink vs Smallest.ai Pulse STT (slim)

> Cartesia Ink scores 67 (B) to Smallest.ai Pulse STT's 65 (B) for speech-to-text. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/cartesia-ink-stt-vs-smallest-pulse-stt.md (~5,950 tokens) · this version ~3,530 tokens · JSON https://www.anchorterminal.com/compare/cartesia-ink-stt-vs-smallest-pulse-stt.json · canonical https://www.anchorterminal.com/compare/cartesia-ink-stt-vs-smallest-pulse-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
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Cartesia Ink scores 67 (B) on agent readiness against Smallest.ai Pulse STT's 65 (B), and leads in 3 of 7 scored categories. Smallest.ai Pulse STT leads on security & auth and payments & pricing. Both do speech-to-text.

- Cartesia Ink: B 67, rank #340 of 1486 · https://www.anchorterminal.com/tools/cartesia-ink-stt.min.md
- Smallest.ai Pulse STT: B 65, rank #441 of 1486 · https://www.anchorterminal.com/tools/smallest-pulse-stt.min.md
- Cartesia Ink, good for Suited to voice agents that need turn detection and transcription from one model in English, French, Hindi, Japanese or Spanish, and to teams already using Cartesia text-to-speech. Ahead on Reliability, 73 against 63; Agent ergonomics, 74 against 66; Maintenance & community, 84 against 73. Also A hosted endpoint, with nothing to install.
- Smallest.ai Pulse STT, good for Low-cost transcription for voice agents and call analytics, with Indic coverage and turn detection. Ahead on Security & auth, 52 against 47; Payments & pricing, 40 against 35.

| Category | Cartesia Ink | Smallest.ai Pulse STT |
| --- | --- | --- |
| Reliability (16%) | 73 | 63 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 89 | 92 |
| Agent ergonomics (13%) | 74 | 66 |
| Security & auth (14%) | 47 | 52 |
| Payments & pricing (10%) | 35 | 40 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 84 | 73 |
| Transparency & trust (7%) | 68 | 71 |

| Fact (where they differ) | Cartesia Ink | Smallest.ai Pulse STT |
| --- | --- | --- |
| Vendor | Cartesia | Smallest AI |
| Hosted endpoint | `https://api.cartesia.ai` | no (local only) |
| Transports | HTTP, websocket, Streamable HTTP | HTTP, websocket |
| Pricing | Freemium | Pay per use |
| Licence | Proprietary hosted service under the Cartesia Terms of Service. The Python and JavaScript SDKs are Apache-2.0 | none |
| Tools exposed | none | 0 |
| Last release | 2026-09-17 | 2026-11-02 |
| Terms last updated | 2024-06-14 | no date given |
| Privacy policy last updated | 2024-06-14 | no date given |
| Customer content may train models | yes, with an opt-out | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Popularity | 134 stars | none |
| Agent reviews | 3.3/5 (4) | none |

Why the edge:
- Maintenance & community, Cartesia Ink +11: Cartesia Ink 84 (Read as a model, on the lines deepgram-stt, gladia-stt and cartesia-tts use for hosted speech models (recency 30, dated releases 10, deprecation notice 10, support 15, issues 10, SDKs 15, health 10). The `cartesia-mcp` server, which has a `speech_to_text` tool, released 0.28.1 on 30 October 2026 with a bug fix, after 0.27.0 (20 October) and 0.28.0 (27 October). The model page still dates `ink-2` and `ink-preview` 17 September 2026 (30). In the 90 days from 3 August the SDKs released 4.0.0, 4.0.1, 4.1.0 and 4.2.0 (14 August to 2 September) and the MCP server several releases, with changelog entries for August and September (10). The deprecations page gives dated sunsets, and Sonic-2, Sonic Turbo and `sonic-3-2025-10-27` were sunset after 20 October 2026, announced in the July changelog. No minimum notice period is stated and no Ink model has been retired, read as cartesia-tts is on the same page (5 of 10). The changelog has speech-to-text entries in May, June, July and September 2026, dated by month only, and no October entry (11 of 15). The Python SDK repository had 4 open issues on 9 October, per that check, not re-read on 1 November since GitHub's pages answered 403 (5 of 10). Official `cartesia` and `@cartesia/cartesia-js` SDKs at 4.2.0 (2 September 2026), generated for API version 2026-08-14 (15). CI workflows, release automation and lock files in both SDK repositories, with dependency updates merged on 23 October (8 of 10). 30 + 10 + 5 + 11 + 5 + 15 + 8 = 84.); Smallest.ai Pulse STT 73 (Read as a model. The newest Pulse changelog entry is dated 2 November 2026 (updated Indic benchmarks), and Pulse 2.0 launched within the period (30). Dated Pulse entries on 30 August, 18, 29 and 30 September, 1, 12, 13 and 21 October and 2 November (20). Public changelog, email support and a Discord server, with no evidence read of how they answer (10 of 15). The Python SDK `smallestai` 5.14.0 dates from 7 October with 12 releases since 9 August, but the npm Node SDK has not been published since May 2025 (8 of 15). The Python SDK repository runs CI and release workflows, but has no licence file (5 of 10). Total 73.)
- Reliability, Cartesia Ink +10: Cartesia Ink 73 (Hosted reading. The status page at status.cartesia.ai (incident.io) lists Speech to Text as its own component in four regions (20). Its RSS feed, re-read on 1 November, now names each incident's components. In the 90 days from 3 August two incidents touch speech-to-text, both partial and read as minor, as this run reads one region or some requests. On 2 September some clients in the US regions saw connection errors that cleared on retry (Text to Speech and Speech to Text, US), and on 7 October customers in the US regions saw higher latency for some API requests, from 12:29 to about 18:23 (partial outage, Text to Speech, Speech to Text and Voice Cloning, US). The 3 September throttling named only Text to Speech in APAC, the 8 October errors only the Playground and Voice Agents, and the 15 October Playground outage says API services were unaffected. The 1 August API-wide incident has left the window. Minor only (20). Concurrency limits are published per plan, 8, 12, 20 and 60 concurrent STT requests, with a 3-minute idle timeout on sockets (15). Exceeding the limit returns 429 with the `concurrency_limited` code, and the SDKs retry 429 and 5xx twice with backoff on HTTP calls. No `Retry-After` header, backoff guidance or reconnection advice for a dropped socket was found (8 of 15). No SLA was found for any plan (0). `ink-2` is marked Stable on the model page re-read on 1 November, with `ink-preview` as the preview line (10). 20 + 20 + 15 + 8 + 0 + 10 = 73.); Smallest.ai Pulse STT 63 (BetterStack status page at status.smallest.ai with components for the Global, India and USA APIs (one health check covers the Agents and Models APIs), docs, the app and Electron, and per-component history (20). In the 90 days from 8 August the health checks on the shared API failed in all three regions on 9, 10, 13, 14 and 15 September (about 8, 21, 33, 17 and 64 minutes of flapping), in the Global and India regions on 11 and 17 September (12 minutes each), and in the USA region alone on 1, 3, 5, 12, 21 and 30 September (6 to 62 minutes) and 6 October (12 minutes). Outages in every region at once are read as wide errors, so several majors (0). Standard plan limits published per model, 100 concurrent streaming sessions and 25 batch requests a minute, and the pricing page also says 100 concurrent STT streams (15). 429 is documented with exponential backoff from 500 ms to 30 s and Retry-After when present, and batch calls are synchronous with optional webhooks (15). An infrastructure SLA of 99.99 per cent is named for Enterprise only, with no terms published, and the terms disclaim any availability commitment (5 of 10). Pulse, Pulse 2.0 and Pulse Pro carry no preview label, but eleven language codes are marked Beta (8 of 10). 20 + 0 + 15 + 15 + 5 + 8 = 63.)
- Agent ergonomics, Cartesia Ink +8: Cartesia Ink 74 (API reading, as for the other speech-to-text listings. Turn events carry a cumulative transcript that is never revised, so an agent reads one `turn.end` a turn, and word timestamps are opt-in on the manual and batch endpoints (20 of 25). There is nothing to page through. Batch takes a file of any length without client chunking, keyterms steer vocabulary, and there is no diarisation or subtitle output (12 of 20). Errors are structured JSON with `error_code`, `title`, `message`, `request_id` and an optional `doc_url` on API version 2026-03-01 and later (17 of 20). Transcription holds no state to duplicate and the SDKs retry failed HTTP calls. A realtime session cannot be resumed, and nothing on reconnecting was found (12 of 20). Realtime needs `model`, `encoding`, `sample_rate` and the version, turn settings have documented defaults, and there are official Python and TypeScript SDKs. Realtime accepts raw PCM only (13 of 15).); Smallest.ai Pulse STT 66 (API reading of the checklist. Word timestamps, utterances, diarisation, emotion and gender are each opt-in, so the default response is the transcript with metadata (18 of 25). There are no list endpoints for transcriptions to page. Output controls are the opt-in fields and finalisation settings on the socket (10 of 20). Errors carry a status and a machine-readable `code` or `error_code` (`LANGUAGE_NOT_SUPPORTED_BY_MODEL`, `AudioTooLong` and others) with fixes, but the body comes in two shapes, `message` or `error` (15 of 20). Batch calls are synchronous with no idempotency key, and whether a retried file is billed again isn't stated (10 of 20). A file call needs only the model and audio. Official Python and Node SDKs exist, though the Node SDK was last published in May 2025 (13 of 15). Total 66.)
- Security & auth, Smallest.ai Pulse STT +5: Cartesia Ink 47 (Model reading. Standard keys (`sk_car_...`) and admin keys are separate types that are not interchangeable, and a server can mint an access token with an `stt` grant that lasts at most one hour. That token travels in the `access_token` query parameter on WebSockets, the API key itself goes in a header, and no key limited to speech-to-text was found. The STT WebSocket definition, re-read on 1 November, lists `access_token` in the query as a security scheme. The checklist takes 10 off for a secret that can travel in a URL query string as a documented option, and this run takes the full 10 for short-lived OAuth tokens in `?access_token=` on every Google API listing, so the earlier 5 is brought into line (26, less 10, 16 of 30). The terms, last revised 14 June 2024, say inputs, outputs and interactions may be used to train models unless otherwise agreed, with an opt-out form in the Playground's data controls (5 of 20). Zero data retention covers STT audio and transcripts and is limited to the Enterprise plan. No retention period for other plans was found, and the DPA gives 180 days for deletion after termination (5 of 15). Credit usage and key metadata are readable through admin endpoints. No audit log was found (7 of 15). security.txt is valid until 3 October 2027 with a contact and a policy link to the trust centre. The docs and pricing page state SOC 2 Type II, HIPAA and PCI-DSS. The trust centre is drawn by script and was not read, and no bug bounty was found (14 of 20). 16 + 5 + 5 + 7 + 14 = 47.); Smallest.ai Pulse STT 52 (Model reading of the checklist, with training and retention in place of the least-privilege and injection lines. Plain `sk_` keys per organisation, shown once, revoked at once and deletable, with one key per environment advised. The docs say a key grants full account access, and no scope is offered. Short-lived access tokens (`wat_`, 30 to 900 seconds) cover only inference routes and can't mint tokens (22 of 30). The error reference documents the key as a `?token=` query parameter for browser WebSockets, and the token guide passes access tokens as `?api_key=` on the STT socket, so 10 off (12 of 30). The terms (21 October 2026) say Smallest won't use user content or input to train or improve its services. The privacy policy (18 September 2026) lists improving the services with machine learning as a use of usage data and doesn't address uploaded audio or text either way (15 of 20). Zero data retention and the `x-expire-content` header are Enterprise only, or a $1,000 a month HIPAA add-on on pay as you go. Other plans keep content readable in logs and the dashboard, with no retention period published (5 of 15). Usage is tracked per key, request rows sit in a dashboard log viewer, and every response carries `x-request-id`. No audit log of key actions was found (10 of 15). security.txt is valid to 31 December 2026 and the site footer claims SOC 2, GDPR and HIPAA compliance, while the pricing page lists SOC 2 compliance only on Enterprise. No bug bounty, disclosure policy or public advisories found (10 of 20). Total 52.)
- Payments & pricing, Smallest.ai Pulse STT +5: Cartesia Ink 35 (No x402, MPP or L402 (0). The docs pricing page gives 3 credits a second for `ink-2` and the public pricing page gives plan prices and overage rates of $65, $45 and $38 per million credits, all read without a login (20). The Free plan is $0 with 20,000 credits a month, about 1 hour 51 minutes of `ink-2` audio. Neither page says whether sign-up asks for a card, and we did not sign up, so 15 of 20. A person creates the key in the Playground in a browser, and the hosted MCP server also needs a browser sign-in (0).); Smallest.ai Pulse STT 40 (No x402, MPP or L402 (0). Per-minute prices for each Pulse model published without a login, with two figures for Pulse Pro (20). Pay as you go starts with $10 of trial credits, which the terms also describe, and no page says a card is needed to claim them, read as inworld-tts's free plan was (20). A person signs up in a browser at app.smallest.ai and creates the key in the dashboard, and top-ups go to a card on file (0). Total 40.)

| Task | Cartesia Ink | Smallest.ai Pulse STT |
| --- | --- | --- |
| Transcribe a one-hour meeting | $0.07 to $0.54 | $0.18 to $0.30 |