ElevenLabs Voice Cloning and Voice Design API vs Inworld Instant Voice Cloning

ElevenLabs Voice Cloning and Voice Design API 84

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. API keys can be limited to chosen endpoints, given a credit quota, user keys can expire after 15 minutes to 30 days, service-account keys exist and accept an expiry of up to 90 days since 26 October, keys can be limited to IP ranges, and leaked keys are disabled through GitHub secret scanning (30). PVC is own-voice only and needs a spoken verification matched to the samples, IVC relies on an attestation, high-risk and celebrity voices are blocked, and an AI speech classifier and C2PA support are public (14 of 20). Training on content is on by default with a self-serve opt-out, and the privacy policy caps voice data retention at 3 years after the last interaction (10 of 15). The History API lists each generation with voice, model, characters and date (15). security.txt valid to 2027-10-06 (re-read on 1 November, contact elevenlabs.io/security/report) with a disclosure programme, SOC 2 Type II, and a trust centre at compliance.elevenlabs.io, no paid bug bounty found (15 of 20).

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.

ElevenLabs Voice Cloning and Voice Design API 91

Public OpenAPI at api.elevenlabs.io/openapi.json, 313 paths per the 6 October check, not re-read on 17 October or 1 November because api.elevenlabs.io's robots.txt now disallows every path (25). llms.txt and Markdown docs, with a .md twin of every page (10). The cloning guides say when to use IVC or PVC and warn that more than 3 minutes of IVC audio can make a clone worse (16 of 20). Inputs are typed, but labels is a free-form map (11 of 15). Plenty of examples, and an errors reference in the API docs lists 10 error types with their HTTP statuses and about 70 named codes, though endpoint pages in the OpenAPI still list only 200 and 422 (14 of 15, up from 10, which read the codes as living only in help-centre articles). Versioned paths (/v1, /v2) and a changelog published several times a month, the latest entries dated 12, 19 and 26 October (15).

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.

ElevenLabs Voice Cloning and Voice Design API 88

Creating a clone returns only voice_id and requires_verification, and GET /v2/voices can be narrowed to personal or cloned voices (25). Cursor pagination with page_size up to 100 and filters by type, category, fine-tuning state and labels (20). Errors carry a type, a named code and a param for validation failures, with recovery hints on many codes such as voice_not_found, invalid_cursor and concurrent_modification, though the two concurrency codes in different pages disagree (18 of 20, up from 15). No idempotency key, PVC exposes fine_tuning_state to poll (10 of 20). Two required fields for an instant clone, and official Python and TypeScript SDKs among others (15).

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.

ElevenLabs Voice Cloning and Voice Design API 83

Closed service with clear terms, SDKs under MIT (15 of 30). Privacy policy updated 9 October 2026 (unchanged on 1 November), still with a 3 year retention cap for voice data and a training opt-out under Data use, a DPA, subprocessors through the compliance portal and a training opt-out that matches the Terms, but the Terms (last updated 9 October 2026, unchanged on 1 November) also take a perpetual, irrevocable licence to User Voice Models while promising deletion on request, which sit uneasily together (25 of 30). Dated deprecations in the changelog, no written notice policy found (15 of 20). Data locations named (United States, the Netherlands, Singapore) and Enterprise residency in the EU, India and Singapore (20).

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.

ElevenLabs Voice Cloning and Voice Design API 85

Python and JavaScript SDK 2.75.0, tagged on 27 October 2026 (23:02 UTC), after 2.74.0 and 2.74.1 on 20 October and 2.73.1 on 17 October (30). Changelog entries weekly, on 5, 12, 19 and 26 October, and seven Python SDK releases in October (20). Public changelog and a help centre, and SDK issues get labels, but the ten newest open issues showed no maintainer replies on 1 October, per the 1 October check, not re-read since (10 of 15). Current official SDKs (15). The Python SDK supports 3.8 and later and shipped five days before this check (10).

Inworld Instant Voice Cloning 68

Read as a model, on the lines inworld-tts and cartesia-voice-cloning use (recency 30, dated releases 10, deprecation notice 10, support 15, SDKs 15, health 10). The 9 October draft used the tool lines and gave 75. @inworld/cli 1.5.0, whose MCP server carries clone_voice, on 29 October 2026, after 1.4.0 (13 October), 1.4.1 (23 October), 1.4.2 and 1.4.3 (25 October) (30). Dated TTS release notes on 9 August and 11 September 2026, and none for the 28 October model update or for the Voice API (10). inworld-tts-1 was discontinued on 15 June 2026 with requests routed to newer models, and clones made before 15 August keep a 15-second prompt, with no notice period stated (5 of 10). A public changelog, a Discord server and support@inworld.ai, with no evidence read of how they answer (8 of 15). @inworld/tts 1.1.1 dates from 6 May 2026 (10 of 15). The CLI is current, but the repositories named in its npm metadata aren't public (5 of 10). 30+10+5+8+10+5 = 68.

ElevenLabs Voice Cloning and Voice Design API 30

No x402, MPP or L402 (0). Per-unit prices for speech from a clone are public, such as $0.08 per 1,000 characters for TTS v4 on the API pricing page (20). The Free plan needs no card, per the 6 October check (the pricing page read on 1 November doesn't say either way), and includes Voice Design, but no cloning (10 of 20). Signup is a human browser flow (0).

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.