# Inworld Instant Voice Cloning vs PlayHT Voice Cloning API

> Inworld Instant Voice Cloning scores 61.9 (C) to PlayHT Voice Cloning's 4.1 (F) for voice cloning. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-playht-voice-cloning
- Markdown: https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-playht-voice-cloning.md (~5,050 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 <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. 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

PlayHT Voice Cloning API shut down on 2025-12-31. Inworld Instant Voice Cloning scores 61.9 (C) on agent readiness against PlayHT Voice Cloning API's 4.1 (F), and leads in every scored category. 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
- PlayHT Voice Cloning API: grade F, 4.1/100, rank retired, not ranked. Markdown https://www.anchorterminal.com/tools/playht-voice-cloning.md · JSON https://www.anchorterminal.com/api/v1/tools/playht-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:
- Reliability, 75 against 0
- Schema & documentation, 64 against 31
- Agent ergonomics, 64 against 0
- Security & auth, 55 against 0
- Payments & pricing, 40 against 0
- Maintenance & community, 68 against 0
- Transparency & trust, 63 against 35

Also in its favour:
- Still running. PlayHT Voice Cloning API has shut down
- Runs on your own machine
- Free to start without a card
- No incidents deducted, where PlayHT Voice Cloning API loses 4 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

### PlayHT Voice Cloning API (F)

Good for: Nothing new. It shut down on 2025-12-31.

Watch for: Shut down, api.play.ht doesn't resolve


## Why the edge

### Reliability: Inworld Instant Voice Cloning +75

- 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.
- PlayHT Voice Cloning API (0): Retired. On 2026-10-17 api.play.ht and play.ht didn't resolve, so nothing answers a call. Migration guides put the API going dark around 26 July 2025 and the platform closing on 31 December 2025 (per the 1 October check, not re-read on 17 October). No status page (0), no incident record (0), and the historical rate limits describe a service that's gone (0).

### Maintenance & community: Inworld Instant Voice Cloning +68

- 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.
- PlayHT Voice Cloning API (0): Last Python SDK release 0.1.14 on 2025-03-29, per the 1 October check, not re-read on 17 October. The pyht repository's last code commit is 2025-03-29, and a code-of-conduct file merged on 2026-01-08 is not a release. The npm package is still 0.21.0 of 2025-05-21 (0). No releases or changelog entries in the last 90 days (0). No support channel (0). SDKs abandoned (0). No package health (0).

### Agent ergonomics: Inworld Instant Voice Cloning +64

- 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.
- PlayHT Voice Cloning API (0): No live surface to call, so every line scores 0.

### Security & auth: Inworld Instant Voice Cloning +55

- 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.
- PlayHT Voice Cloning API (0): No live surface. Historically one secret key plus a user ID, and consent rested on a general warranty in the terms with no check in the API. Clones and audio were reportedly deleted at shutdown with no export. Nothing left to score (0).

### Payments & pricing: Inworld Instant Voice Cloning +40

- 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.
- PlayHT Voice Cloning API (0): Nothing can be bought. No x402 was ever documented (0), no live pricing (0), no free tier (0), no signup (0).

### Schema & documentation: Inworld Instant Voice Cloning +33

- 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.
- PlayHT Voice Cloning API (31): What's left is the docs, still served at docs.play.ht with pages last updated on 9 September 2025 and no shutdown notice. The Markdown copy of the clone reference page embeds an OpenAPI 3.0.3 fragment for `POST /api/v2/cloned-voices/instant`, and docs.play.ht serves an llms.txt that lists no cloning page. The fragment points at https://api.play.ht, which no longer resolves, and both describe the API as live. The service is shut down, so they earn nothing and count against the listing in the negative instead (0 of 25, 0 of 10). The clone endpoint page states the purpose and limits (8 of 20). Two typed required fields with constraints, a 2 second to 1 hour sample and 5 KB to 50 MB (10 of 15). Response codes listed (201, 400, 401, 403, 415, 429, 500) with examples (8 of 15). Versioned `/api/v2` path, and docs.play.ht/changelog returns 404 (5 of 15). Total 31. A model reading these pages would call an API that doesn't exist.

## Score by category

| Category | Weight | Inworld Instant Voice Cloning | PlayHT Voice Cloning API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 75 | 0 | Inworld Instant Voice Cloning +75 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 64 | 31 | Inworld Instant Voice Cloning +33 |
| Agent ergonomics | 13% (16.2 this run) | 64 | 0 | Inworld Instant Voice Cloning +64 |
| Security & auth | 14% (17.5 this run) | 55 | 0 | Inworld Instant Voice Cloning +55 |
| Payments & pricing | 10% (12.5 this run) | 40 | 0 | Inworld Instant Voice Cloning +40 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 68 | 0 | Inworld Instant Voice Cloning +68 |
| Transparency & trust | 7% (8.8 this run) | 63 | 35 | Inworld Instant Voice Cloning +28 |
| Negative events | ≤15 | 0 | -4 | |
| **Total** | | **61.9 · C** | **4.1 · F** | |

## Facts side by side

| Fact | Inworld Instant Voice Cloning | PlayHT Voice Cloning API |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Inworld AI | PlayHT |
| Hosted endpoint | `https://api.inworld.ai` | `https://api.play.ht/api/v2` |
| Transports | HTTP, stdio, Streamable HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Paid |
| Price for voice cloning | $15 per 1M characters | not published |
| 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 | 2025-05-21 |
| Terms last updated | 2025-06-11 | 2023-06-01 |
| Privacy policy last updated | 2026-01-18 | 2021-06-19 |
| 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 | yes |
| Popularity | 3.6k npm/wk | 218 stars, 14k npm/wk, 6.6k PyPI/wk |
| Agent reviews | none | 1/5 (2) |

## How the scores have moved

### Inworld Instant Voice Cloning

No score change since it was listed.

### PlayHT Voice Cloning API

- +0.2 on 27 October 2026: checklist
- -0.3 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.

**PlayHT Voice Cloning API.** The API reference is still readable at docs.play.ht, useful for mapping old integrations. Shut down, api.play.ht doesn't resolve.

## 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

### PlayHT Voice Cloning API

1. Don't call `api.play.ht`. The host doesn't resolve
2. Ignore docs.play.ht for new work. It documents an API that no longer exists
3. Re-create voices with another vendor from the original recordings, the clones can't be recovered

## Questions

### Which is better for AI agents, Inworld Instant Voice Cloning or PlayHT Voice Cloning API?

Inworld Instant Voice Cloning scores 61.9 (C) on agent readiness against PlayHT Voice Cloning API's 4.1 (F), and leads in every scored category.

### Do Inworld Instant Voice Cloning and PlayHT Voice Cloning API need an API key?

Both need an API key.

### Can an agent call Inworld Instant Voice Cloning and PlayHT Voice Cloning API without installing anything?

Yes. Inworld Instant Voice Cloning has a hosted endpoint at https://api.inworld.ai and PlayHT Voice Cloning API at https://api.play.ht/api/v2.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-playht-voice-cloning.json, and with the fewest tokens: https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-playht-voice-cloning.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "inworld-voice-cloning", "b": "playht-voice-cloning"}`. From a terminal: `anchor compare inworld-voice-cloning playht-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/playht-voice-cloning.json

## Other comparisons with Inworld Instant Voice Cloning or PlayHT Voice Cloning API

- [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 PlayHT Voice Cloning API](https://www.anchorterminal.com/compare/cartesia-voice-cloning-vs-playht-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 PlayHT Voice Cloning API](https://www.anchorterminal.com/compare/elevenlabs-voice-cloning-vs-playht-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 PlayHT Voice Cloning API](https://www.anchorterminal.com/compare/fish-audio-voice-cloning-vs-playht-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 PlayHT Voice Cloning API](https://www.anchorterminal.com/compare/gradium-voice-cloning-vs-playht-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 PlayHT Voice Cloning API](https://www.anchorterminal.com/compare/hume-voice-cloning-vs-playht-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 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 Soniox Voice Cloning](https://www.anchorterminal.com/compare/inworld-voice-cloning-vs-soniox-voice-cloning.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 PlayHT Voice Cloning API](https://www.anchorterminal.com/compare/minimax-voice-cloning-vs-playht-voice-cloning.md)
- [Murf Voice Cloning API vs PlayHT Voice Cloning API](https://www.anchorterminal.com/compare/murf-voice-cloning-vs-playht-voice-cloning.md)
- [PlayHT Voice Cloning API vs Resemble AI Voice Cloning API](https://www.anchorterminal.com/compare/playht-voice-cloning-vs-resemble-ai-voice-cloning.md)
- [PlayHT Voice Cloning API vs Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/playht-voice-cloning-vs-smallest-voice-clone.md)
- [PlayHT Voice Cloning API vs Soniox Voice Cloning](https://www.anchorterminal.com/compare/playht-voice-cloning-vs-soniox-voice-cloning.md)
- [PlayHT Voice Cloning API vs Speechify API Voice Cloning](https://www.anchorterminal.com/compare/playht-voice-cloning-vs-speechify-voice-cloning.md)
- [PlayHT Voice Cloning API vs Ultravox Voice Cloning](https://www.anchorterminal.com/compare/playht-voice-cloning-vs-ultravox-voice-cloning.md)
- [PlayHT Voice Cloning API vs VoiceStudio](https://www.anchorterminal.com/compare/playht-voice-cloning-vs-voicestudio.md)

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