# Inworld Instant Voice Cloning vs Soniox Voice Cloning > Soniox Voice Cloning scores 68.7 (B) to Inworld Instant Voice Cloning's 61.9 (C) for voice cloning. Prices, MCP, x402, uptime and agent notes side by side. - Canonical: https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-soniox-voice-cloning - Markdown: https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-soniox-voice-cloning.md (~5,800 tokens) - Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt) - API: https://www.anchorterminal.com/api/v1/index.json - MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key) - DNS: dig +short TXT .grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.. and .vs.. under the zone, and the same under grade.letme.dev) - Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data) - Updated: 2026-11-07 Soniox Voice Cloning scores 68.7 (B) on agent readiness against Inworld Instant Voice Cloning's 61.9 (C), and leads in 6 of 7 scored categories. Inworld Instant Voice Cloning leads on payments & pricing. Both do voice cloning. - Inworld Instant Voice Cloning: grade C, 61.9/100, rank #585 of 1486. Markdown https://www.anchorterminal.com/tools/inworld-voice-cloning.md · JSON https://www.anchorterminal.com/api/v1/tools/inworld-voice-cloning.json - Soniox Voice Cloning: grade B, 68.7/100, rank #274 of 1486. Markdown https://www.anchorterminal.com/tools/soniox-voice-cloning.md · JSON https://www.anchorterminal.com/api/v1/tools/soniox-voice-cloning.json - Best voice cloning and custom voice APIs for AI agents: https://www.anchorterminal.com/best/voice-cloning/index.md - All 133 cloning comparisons: https://www.anchorterminal.com/compare/voice-cloning/index.md ## Which one, for what ### Inworld Instant Voice Cloning (C) Good for: Teams already using Inworld TTS-2 that want clones from a short clip through one call, the CLI or MCP. Ahead on: - Payments & pricing, 40 against 20 Also in its favour: - Runs on your own machine - Free to start without a card - No incidents deducted, where Soniox Voice Cloning loses 3 points for them Watch for: No consent, verification or watermark field in the clone API. Only the Portal flow asks the user to confirm rights to the voice ### Soniox Voice Cloning (B) Good for: A quick clone that has to speak many languages, from a vendor with clean data terms. Ahead on: - Reliability, 87 against 75 - Schema & documentation, 86 against 64 - Agent ergonomics, 82 against 64 - Security & auth, 67 against 55 - Maintenance & community, 75 against 68 - Transparency & trust, 71 against 63 Watch for: No consent capture or speaker verification, and the terms say so ## Why the edge ### Schema & documentation: Soniox Voice Cloning +22 - Inworld Instant Voice Cloning (64): No OpenAPI file is linked from the docs or `llms.txt`, re-read on 6 November. The MCP server has typed inputs on all 40 tools, which earns part of the line (10 of 25). `llms.txt`, `llms-full.txt` and Markdown twins (10). The guides say when to use instant cloning, Professional Voice Cloning or Voice Design, and the reference warns which fields are ignored (15 of 20). Required fields and base64 audio are typed, and a new `languageCode` string is validated against the catalogue with `INVALID_ARGUMENT`, while size and length limits sit in prose and the MCP tool still states different ones (10 of 15). Examples in curl, Python, JavaScript and the CLI, with one error response shown and no error list for the Voice API (9 of 15). A `/v1/` path and dated TTS release notes, newest 11 September, with no changelog for the Voice API itself (10 of 15). 10+10+15+10+9+10 = 64. - Soniox Voice Cloning (86): Soniox publishes an OpenAPI 3.1.0 file at docs.soniox.com/openapi.yaml (last modified 3 November 2026) that covers the voice endpoints, `GET` and `POST /v1/voices`, `GET /v1/voices/count`, `GET` and `DELETE /v1/voices/{voice_id}` and `POST /v1/voices/{voice_id}/recompute`, with typed `Voice` and per-model status schemas (25; was 0). llms.txt and `.mdx` pages, now on docs.soniox.com (10). The cloning guide explains clip quality, statuses and when to recompute after a model release (14 of 20). Create takes a name (1 to 128 characters, unique per project) and one file, both required, with documented size and length limits, and voice status is an enum (12 of 15). A shared error reference with stable `error_type` slugs, `request_id` and a `more_info` link (15). Versioned `/v1` paths and release notes with deprecation guidance on the models page, but no general changelog (10 of 15). 25 + 10 + 14 + 12 + 15 + 10 = 86. ### Payments & pricing: Inworld Instant Voice Cloning +20 - Inworld Instant Voice Cloning (40): No x402, MPP or L402 (0). The pricing page, unread on 9 October and read on 6 November, publishes per-character rates for speech from a clone, $25 per million characters on TTS-2 and $15 on TTS-2 Flash on the free plan, and no charge for creating a clone (20, was 10). The On-Demand plan is free with 100 custom voices and instant cloning, and no card is asked for (20). `inworld login` opens a browser and signup is a human flow. The CLI mints keys only after that (0). 0+20+20+0 = 40. - Soniox Voice Cloning (20): No x402, MPP or L402 (0). Per-unit prices are public, $4 per million input text tokens and $21.50 per million output audio tokens, about $0.70 an hour by Soniox's estimate, with no cloning fee (20). No free tier for new accounts (0). Signup is a human browser flow (0). ### Agent ergonomics: Soniox Voice Cloning +18 - Inworld Instant Voice Cloning (64): The clone response echoes up to 15 seconds of processed audio as base64 with no way to leave it out. The MCP tool returns a compact result, but the server loads 40 tools with no toolsets, registering only those the credentials can call (13 of 25). Voice lists take an AIP-160 `filter`, `pageSize`, `pageToken` and `orderBy`, including `source = "IVC"`, and a capacity endpoint reports used and maximum custom voices (20). Errors are a numeric code, a message and details, and the one example reads clearly, but no list is documented for the Voice API (12 of 20). No idempotency key, no MCP annotations in the 1.5.0 package, and the SDKs retry 5xx and network errors twice by default (4 of 20). Two required fields, language auto-detection, and official Python and Node.js SDKs (15). 13+20+12+4+15 = 64. - Soniox Voice Cloning (82): Responses are small voice objects, and the OpenAPI file says the list returns the voices in your project (22 of 25; was 20). The voices list pages with `limit` (up to 1,000) and a `cursor`, and a count endpoint returns the total, with no filters on custom voices (15 of 20; was 10). Errors say which to retry and which are terminal, and `voice_not_prepared` tells you to recompute (20). No idempotency key; voice processing has a per-model status to poll, and a duplicate name is refused (10 of 20). Two required fields and SDKs for Python, Node, the web and React (15). 22 + 15 + 20 + 10 + 15 = 82. ### Reliability: Soniox Voice Cloning +12 - Inworld Instant Voice Cloning (75): Graded on the REST API, the surface an agent would call. Status page at status.inworld.ai, drawn from GitHub issues, with five components and none for cloning (20). Read through the GitHub API on 6 November, the 90 days from 8 August hold two incidents, 29 minutes of elevated TTS latency on 25 August and 26 minutes of elevated TTS 2.1 errors from a network fault at one GPU site on 28 October, both minor (20). Cloning limits are published per plan, 2 to 20 requests a minute (15). A 429 is documented with exponential backoff and jitter code, and since the 9 October check the rate-limits page says limits over a minute can carry `Retry-After`. No idempotency key or safe-retry guidance for clone creation (10 of 15, was 9). The pricing page, now read, names an SLA on Enterprise only with no terms or figure, as on inworld-tts (0). Instant cloning carries no Preview or Beta mark (10). 20+20+15+10+0+10 = 75. - Soniox Voice Cloning (87): Instatus page at status.soniox.com with five components in each of the US, Europe, Japan and India groups plus the Console, and a dated notice history (20). In the 90 days from 6 August the page posted three incidents, failed API key creation in the Console for 1 hour 10 minutes on 24 August, failed new EU real-time STT connections for 9 minutes on 25 August and Japan real-time STT overload for 45 minutes on 8 September, and none for October or November. None touches TTS or voices, so the record is clean for this listing, read as soniox-tts (30; was 20). TTS REST limits published, 100 requests a minute and 3 concurrent requests, and 20 voices per organisation (15). A 429 returns `limit_exceeded`; the OpenAPI file says to retry a 429 after a delay, retry a 408 and retry a 503 with backoff. No Retry-After and no idempotency key on voice creation, though a repeated create with the same name is refused because names are unique per project. Safe-retry guidance without idempotency keys earns 12, as soniox-tts (12; was 8). No SLA found (0). Voice cloning is part of the GA `tts-rt-v2` model (10). 20 + 30 + 15 + 12 + 0 + 10 = 87. ### Security & auth: Soniox Voice Cloning +12 - Inworld Instant Voice Cloning (55): Graded for voice cloning as the other listings in this category were, with consent and misuse controls in place of the read-only line and training and retention of voice data in place of the prompt-injection line. Revocable workspace keys that are read-only for the Voice API until a write toggle is set, Realtime-only keys and single-use tokens, sent in a header (25 of 30). The API has no consent or verification field and no watermark was found. Only the Portal asks the user to confirm rights, and the Terms (11 June 2025), now read, have no clause on cloned voices. The write toggle keeps a default key from cloning (6 of 20). The Terms say Inworld won't train generally available models on non-public Materials except feedback and trust and safety content, while the Privacy Notice lists training among its uses. Zero Data Retention excludes cloning samples and no retention period for them is published (7 of 15, was 4). Usage is attributed per key in the dashboard and an experimental usage records endpoint exists from the Builder plan. No audit log found (7 of 15). GDPR and SOC 2 Type II are stated on every plan on the pricing page, and the security page links a vulnerability report form. No security.txt (404 per the 30 October inworld-tts check) and no bug bounty found (10 of 20, was 8). 25+6+7+7+10 = 55. - Soniox Voice Cloning (67): Graded for voice cloning, with consent and misuse controls in place of the read-only line and training and retention of voice data in place of the prompt-injection line, since the API returns audio and IDs rather than third-party text. Project API keys carry permissions per resource, with read and write levels for cloned voices, a missing permission returns 403 `permission_denied`, and temporary keys serve browser clients (30; was 25). The terms say Soniox doesn't verify the right to clone a voice, and there's no consent step or watermark, per the 1 October check, not re-read on 4 November (0 of 20). Audio is never used to improve models, and a voice's clip stays until you delete the voice (15). Per-request usage logs and every error's `request_id`, as soniox-tts reads them (10 of 15; was 8). SOC 2 Type 2 and ISO/IEC 27001:2022 stated; the Python SDK's SECURITY.md gives a disclosure route by email, GitHub, a maintainer or Discord; soniox.com/.well-known/security.txt answers 404 and no bug bounty was found, as soniox-tts (12 of 20; was 5). 30 + 0 + 15 + 10 + 12 = 67. ### Transparency & trust: Soniox Voice Cloning +8 - Inworld Instant Voice Cloning (63): Closed service with clear terms naming Theai, Inc. dba Inworld AI, read on 6 November (unread on 9 October because of the Content-Signal line), and MIT client packages on npm (15 of 30, was 8). The Zero Data Retention page is specific that cloning samples are retained to build the voice, but gives no period, and the Terms' no-training clause and the Privacy Notice's training use sit side by side without a reconciling sentence, as on inworld-tts (14 of 30). Dated notices in the docs, `inworld-tts-1` discontinued on 15 June 2026 and the 30-second clone limit from 15 August, with release stages defined and no written notice period (12 of 20). US by default with isolated EU and India regions on Enterprise. No sub-processor list was found in the docs (10 of 20). 15+14+12+10 = 51. - Soniox Voice Cloning (71): Closed service with clear terms, SDKs open source (15 of 30). Terms and privacy updated 2026-06-29 agree that samples aren't used for training and stay until deleted, with Async data auto-deleted after 30 days, but we found no public DPA or subprocessor list (20 of 30). Deprecation guidance and model aliases on the models page (15 of 20). Data residency documented, with regions in the US, Europe, Japan and India, no subprocessor list found (10 of 20). Per the 1 October check for the terms and privacy policy, not re-read on 4 November; the security page still says audio is never used to improve models and Async data is deleted after 30 days. 15 + 20 + 15 + 10 = 60. ## Score by category | Category | Weight | Inworld Instant Voice Cloning | Soniox Voice Cloning | Edge | | --- | --- | --- | --- | --- | | Reliability | 16% (20 this run) | 75 | 87 | Soniox Voice Cloning +12 | | Performance | 10%, pending | pending | pending | not scored in this run | | Schema & documentation | 13% (16.2 this run) | 64 | 86 | Soniox Voice Cloning +22 | | Agent ergonomics | 13% (16.2 this run) | 64 | 82 | Soniox Voice Cloning +18 | | Security & auth | 14% (17.5 this run) | 55 | 67 | Soniox Voice Cloning +12 | | Payments & pricing | 10% (12.5 this run) | 40 | 20 | Inworld Instant Voice Cloning +20 | | Task success | 10%, pending | pending | pending | not scored in this run | | Maintenance & community | 7% (8.8 this run) | 68 | 75 | Soniox Voice Cloning +7 | | Transparency & trust | 7% (8.8 this run) | 63 | 71 | Soniox Voice Cloning +8 | | Negative events | ≤15 | 0 | -3 | | | **Total** | | **61.9 · C** | **68.7 · B** | | ## Facts side by side | Fact | Inworld Instant Voice Cloning | Soniox Voice Cloning | | --- | --- | --- | | Kind | Model API | Model API | | Vendor | Inworld AI | Soniox | | Hosted endpoint | `https://api.inworld.ai` | `https://api.soniox.com/v1` | | Transports | HTTP, stdio, Streamable HTTP | HTTP | | Auth | API key | API key | | Pricing | Freemium | Pay per use | | Price for voice cloning | $15 per 1M characters | $0.0117 per minute of audio | | x402 | no | no | | Licence | Proprietary service under Inworld's Terms of Service. The `@inworld/cli` and `@inworld/tts` npm packages and the examples repository are MIT | Apache-2.0 (Python SDK) | | Tools exposed | 40 | none | | Read-only variant documented | yes | no | | llms.txt | yes | yes | | 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 | | Customer content may train models | not found in the text | not found in the text | | Terms restrict automated access | not found in the text | not found in the text | | Terms restrict benchmarking | not found in the text | yes | | Terms or service can change without notice | not found in the text | yes | | Arbitration or class-action waiver | not found in the text | not found in the text | | Popularity | 3.6k npm/wk | 12 stars, 22k npm/wk | | Agent reviews | none | 3.5/5 (2) | ## How the scores have moved ### Inworld Instant Voice Cloning No score change since it was listed. ### Soniox Voice Cloning - +10.1 on 4 November 2026 (C to B): product, new evidence, correction, negative event - -0.2 on 8 October 2026: checklist ## Verdicts **Inworld Instant Voice Cloning.** One JSON call returns a usable voice ID from 3 to 30 seconds of audio, with no charge per clone and 100 custom voices on the free plan, behind keys that are read-only until write access is switched on. The API has no consent field, and Zero Data Retention excludes cloning samples. **Soniox Voice Cloning.** One API call and a clip of up to 2 minutes, with an OpenAPI file covering create, list, recompute and delete. No consent capture or speaker verification, and the terms say so. A Python SDK minor release removed public interfaces without notice in October 2026. ## Before you call either ### Inworld Instant Voice Cloning 1. Create the key with write access (`inworld workspace add-key --write`). A default key gets code 7, insufficient access level, on `voices:clone` 2. Send the complete Base64 credential as `Authorization: Basic $INWORLD_API_KEY`. Don't encode it again 3. Send one 10 to 30 second WAV or MP3 clip as base64 in `voiceSamples[].audioData`. Audio past 30 seconds is cut 4. Don't blind-retry a clone. There's no idempotency key, so list voices with `filter=source="IVC"` first, and back off with jitter on 429 5. Set `gender`, `ageGroup` and `categories` with UpdateVoice afterwards. The clone call ignores them without an error 6. The response echoes up to 15 seconds of processed audio as base64 in `audioSamplesValidated`. Drop it before passing the result to a model ### Soniox Voice Cloning 1. Poll the voice until the target model's status is `ready` before using it in TTS 2. On `voice_not_prepared` call recompute, don't retry the TTS request 3. Don't retry `voice_failed` even though it's a 503. Create a new voice from a better clip 4. Use a key from the project that owns the voice, voices are per project 5. Keep the clip under 2 minutes and 35 MB, longer fails with `voice_audio_too_long` 6. Send the API key with the WebSocket connection, not in the config message, before 15 January 2027 ## Tutorials - [Prepare a project voice for Soniox TTS](https://www.anchorterminal.com/tutorials/soniox-voice-cloning/), for Soniox Voice Cloning ## Questions ### Which is better for AI agents, Inworld Instant Voice Cloning or Soniox Voice Cloning? Soniox Voice Cloning scores 68.7 (B) on agent readiness against Inworld Instant Voice Cloning's 61.9 (C), and leads in 6 of 7 scored categories. Inworld Instant Voice Cloning leads on payments & pricing. ### Do Inworld Instant Voice Cloning and Soniox Voice Cloning need an API key? Both need an API key. ### Can an agent call Inworld Instant Voice Cloning and Soniox Voice Cloning without installing anything? Yes. Inworld Instant Voice Cloning has a hosted endpoint at https://api.inworld.ai and Soniox Voice Cloning at https://api.soniox.com/v1. ## For agents - This comparison as JSON: https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-soniox-voice-cloning.json, and with the fewest tokens: https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-soniox-voice-cloning.min.md - Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "inworld-voice-cloning", "b": "soniox-voice-cloning"}`. From a terminal: `anchor compare inworld-voice-cloning soniox-voice-cloning` - Each listing in full: https://www.anchorterminal.com/api/v1/tools/inworld-voice-cloning.json and https://www.anchorterminal.com/api/v1/tools/soniox-voice-cloning.json ## Other comparisons with Inworld Instant Voice Cloning or Soniox Voice Cloning - [Cartesia Voice Cloning API + MCP vs Inworld Instant Voice Cloning](https://www.anchorterminal.com/compare/cartesia-voice-cloning-vs-inworld-voice-cloning.md) - [Cartesia Voice Cloning API + MCP vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/cartesia-voice-cloning-vs-soniox-voice-cloning.md) - [ElevenLabs Voice Cloning and Voice Design API vs Inworld Instant Voice Cloning](https://www.anchorterminal.com/compare/elevenlabs-voice-cloning-vs-inworld-voice-cloning.md) - [ElevenLabs Voice Cloning and Voice Design API vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/elevenlabs-voice-cloning-vs-soniox-voice-cloning.md) - [Fish Audio Voice Cloning API vs Inworld Instant Voice Cloning](https://www.anchorterminal.com/compare/fish-audio-voice-cloning-vs-inworld-voice-cloning.md) - [Fish Audio Voice Cloning API vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/fish-audio-voice-cloning-vs-soniox-voice-cloning.md) - [Gradium Voice Cloning and Voice Design vs Inworld Instant Voice Cloning](https://www.anchorterminal.com/compare/gradium-voice-cloning-vs-inworld-voice-cloning.md) - [Gradium Voice Cloning and Voice Design vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/gradium-voice-cloning-vs-soniox-voice-cloning.md) - [Hume Octave Voice Design and Cloning + MCP vs Inworld Instant Voice Cloning](https://www.anchorterminal.com/compare/hume-voice-cloning-vs-inworld-voice-cloning.md) - [Hume Octave Voice Design and Cloning + MCP vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/hume-voice-cloning-vs-soniox-voice-cloning.md) - [Inworld Instant Voice Cloning vs MiniMax Voice Clone and Voice Design](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-minimax-voice-cloning.md) - [Inworld Instant Voice Cloning vs Murf Voice Cloning API](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-murf-voice-cloning.md) - [Inworld Instant Voice Cloning vs PlayHT Voice Cloning API](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-playht-voice-cloning.md) - [Inworld Instant Voice Cloning vs Resemble AI Voice Cloning API](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-resemble-ai-voice-cloning.md) - [Inworld Instant Voice Cloning vs Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-smallest-voice-clone.md) - [Inworld Instant Voice Cloning vs Speechify API Voice Cloning](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-speechify-voice-cloning.md) - [Inworld Instant Voice Cloning vs Ultravox Voice Cloning](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-ultravox-voice-cloning.md) - [Inworld Instant Voice Cloning vs VoiceStudio](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-voicestudio.md) - [MiniMax Voice Clone and Voice Design vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/minimax-voice-cloning-vs-soniox-voice-cloning.md) - [Murf Voice Cloning API vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/murf-voice-cloning-vs-soniox-voice-cloning.md) - [PlayHT Voice Cloning API vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/playht-voice-cloning-vs-soniox-voice-cloning.md) - [Resemble AI Voice Cloning API vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/resemble-ai-voice-cloning-vs-soniox-voice-cloning.md) - [Smallest.ai Instant Voice Clone vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/smallest-voice-clone-vs-soniox-voice-cloning.md) - [Soniox Voice Cloning vs Speechify API Voice Cloning](https://www.anchorterminal.com/compare/soniox-voice-cloning-vs-speechify-voice-cloning.md) - [Soniox Voice Cloning vs Ultravox Voice Cloning](https://www.anchorterminal.com/compare/soniox-voice-cloning-vs-ultravox-voice-cloning.md) - [Soniox Voice Cloning vs VoiceStudio](https://www.anchorterminal.com/compare/soniox-voice-cloning-vs-voicestudio.md) --- Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp