# Smallest.ai Instant Voice Clone vs Soniox Voice Cloning

> Soniox Voice Cloning scores 68.7 (B) to Smallest.ai Instant Voice Clone's 58 (C) for voice cloning. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/smallest-voice-clone-vs-soniox-voice-cloning
- Markdown: https://www.anchorterminal.com/compare/smallest-voice-clone-vs-soniox-voice-cloning.md (~4,950 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

Soniox Voice Cloning scores 68.7 (B) on agent readiness against Smallest.ai Instant Voice Clone's 58 (C), and leads in 5 of 7 scored categories. Both do voice cloning.

- Smallest.ai Instant Voice Clone: grade C, 58/100, rank #768 of 1486. Markdown https://www.anchorterminal.com/tools/smallest-voice-clone.md · JSON https://www.anchorterminal.com/api/v1/tools/smallest-voice-clone.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

### Smallest.ai Instant Voice Clone (C)

Good for: Teams already on Smallest's Lightning TTS or voice agents who want a clone from a short clip in one call.

Also in its favour:
- No incidents deducted, where Soniox Voice Cloning loses 3 points for them

Watch for: The endpoint defaults to `lightning-v3.1`, whose clones stop working on 30 November 2026

### 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 65
- Schema & documentation, 86 against 70
- Agent ergonomics, 82 against 62
- Security & auth, 67 against 48

Watch for: No consent capture or speaker verification, and the terms say so


## Why the edge

### Reliability: Soniox Voice Cloning +22

- Smallest.ai Instant Voice Clone (65): Graded on the hosted cloning API with the hosted lines. status.smallest.ai is the vendor's own status page with components per region and a dated incident feed (20). The feed, read on 6 November, has dozens of automated outage alerts on the API components in the 90 days from 8 August, most a few minutes long, and a cluster across every API region from 13 to 17 September. The 60-day uptime bars read 99.790 per cent for API USA and 99.849 per cent for API Global. No single outage of an hour was found, but repeated wide outages read as one major episode (10). Rate limits are published for TTS (one concurrent request, 100 a minute on pay as you go), while the per-organisation clone limit has no number (10 of 15). The limits page says to handle 429 gracefully and the clone errors say to retry a timeout, with no Retry-After, backoff figures or idempotency key (5 of 15). The pricing table lists an Enterprise SLA of 99.99 per cent (10). Instant cloning carries no beta label (10). 20+10+10+5+10+10 = 65.
- 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.

### Agent ergonomics: Soniox Voice Cloning +20

- Smallest.ai Instant Voice Clone (62): The clone response is a compact object with the voice ID, status and signed URLs to sample clips rather than inline audio (20 of 25). The list call returns every clone on the organisation with no pagination or filter found (10 of 20). Errors carry a message and, on 500, an `error_code` enum with a stated fix, such as retrying `voice_clone_timeout` (16 of 20). No idempotency key, and retrying a timeout can leave a duplicate clone, with deletion through an oddly named route (4 of 20). Two required fields. The Python SDK `smallestai` 5.14.0 is current, while the npm package `smallestai` was last published on 16 April 2025 (12 of 15). 20+10+16+4+12 = 62.
- 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.

### Security & auth: Soniox Voice Cloning +19

- Smallest.ai Instant Voice Clone (48): Graded for voice cloning as the other listings in this category, 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. Plain bearer keys, shown once, revocable, with rotation guidance and no scopes. Short-lived access tokens are refused on the cloning endpoint (20 of 30). No consent or verification field. The Terms let Smallest demand proof that the speaker authorised a clone and remove voices without it, and the prohibited use policy bars unauthorised impersonation. No watermark found (6 of 20). The Terms say Smallest won't use User Content or Input to train its services. Zero retention and retention windows are Enterprise options, and no retention period for samples is published (9 of 15). A usage dashboard, with no audit log found (5 of 15). A valid security.txt naming security@smallest.ai and a HIPAA business associate agreement page. The trust centre didn't answer through our proxy, so no certification was confirmed first-hand, and no bug bounty was found (8 of 20). 20+6+9+5+8 = 48.
- 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.

### Schema & documentation: Soniox Voice Cloning +16

- Smallest.ai Instant Voice Clone (70): The API reference pages are generated with typed fields, enums and error schemas, but no OpenAPI file was found linked from the docs or llms.txt (5 of 25). llms.txt and a Markdown copy of every page (10). The guide says when to use the Pro pool, how to check `modelIds` before synthesis and why a mismatched clone returns empty audio, while the reference still names the retiring default (14 of 20). `model` and `language` are enums validated by the server, with required `displayName` and `file`, a 5 MB limit and MIME types listed, and `tags` as a comma-separated string (12 of 15). Examples in curl, Python and Node.js and a table of seven error cases with causes (14 of 15). Paths under `/v1`, a deprecation page with dated statuses and a models changelog with entries on 21, 24, 26, 28 and 29 October 2026 (15). 5+10+14+12+14+15 = 70.
- 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.

## Score by category

| Category | Weight | Smallest.ai Instant Voice Clone | Soniox Voice Cloning | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 65 | 87 | Soniox Voice Cloning +22 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 70 | 86 | Soniox Voice Cloning +16 |
| Agent ergonomics | 13% (16.2 this run) | 62 | 82 | Soniox Voice Cloning +20 |
| Security & auth | 14% (17.5 this run) | 48 | 67 | Soniox Voice Cloning +19 |
| Payments & pricing | 10% (12.5 this run) | 20 | 20 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 72 | 75 | Soniox Voice Cloning +3 |
| Transparency & trust | 7% (8.8 this run) | 72 | 71 | Smallest.ai Instant Voice Clone +1 |
| Negative events | ≤15 | 0 | -3 | |
| **Total** | | **58 · C** | **68.7 · B** | |

## Facts side by side

| Fact | Smallest.ai Instant Voice Clone | Soniox Voice Cloning |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Smallest, Inc. | Soniox |
| Hosted endpoint | `https://api.smallest.ai/waves/v1/voice-cloning` | `https://api.soniox.com/v1` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| Price for voice cloning | $17.50 per 1M characters | $0.0117 per minute of audio |
| x402 | no | no |
| Licence | Proprietary service under Smallest's Terms of Service. The `smallestai` Python SDK is on PyPI | Apache-2.0 (Python SDK) |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-29 | 2026-11-03 |
| Terms last updated | no date given | 2026-06-29 |
| Privacy policy last updated | no date given | 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 | yes | yes |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | none | 12 stars, 22k npm/wk |
| Agent reviews | none | 3.5/5 (2) |

## How the scores have moved

### Smallest.ai Instant Voice Clone

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

**Smallest.ai Instant Voice Clone.** One multipart POST clones a voice from 5 to 15 seconds of audio and returns sample clips, with dated deprecation notices and current changelog entries. The endpoint still defaults to a model whose clones stop working on 30 November 2026, there's no consent field or clone price, and the status feed shows frequent short API outages.

**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

### Smallest.ai Instant Voice Clone

1. Always pass `model=lightning-v3.1-pro`. The default `lightning-v3.1` clones stop working on 30 November 2026
2. Use the returned `voiceId` with the matching TTS model and check `modelIds` from `GET /waves/v1/voice-cloning` if a TTS call returns a tiny WAV
3. Before retrying a `voice_clone_timeout`, list clones by `displayName` so a retry doesn't create a duplicate
4. Send the server API key, not an access token. The cloning endpoint refuses short-lived tokens
5. Keep TTS calls from a clone to one at a time on the self-serve plan and back off on 429

### 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, Smallest.ai Instant Voice Clone or Soniox Voice Cloning?

Soniox Voice Cloning scores 68.7 (B) on agent readiness against Smallest.ai Instant Voice Clone's 58 (C), and leads in 5 of 7 scored categories.

### Do Smallest.ai Instant Voice Clone and Soniox Voice Cloning need an API key?

Both need an API key.

### Can an agent call Smallest.ai Instant Voice Clone and Soniox Voice Cloning without installing anything?

Yes. Smallest.ai Instant Voice Clone has a hosted endpoint at https://api.smallest.ai/waves/v1/voice-cloning and Soniox Voice Cloning at https://api.soniox.com/v1.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/smallest-voice-clone-vs-soniox-voice-cloning.json, and with the fewest tokens: https://www.anchorterminal.com/compare/smallest-voice-clone-vs-soniox-voice-cloning.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "smallest-voice-clone", "b": "soniox-voice-cloning"}`. From a terminal: `anchor compare smallest-voice-clone soniox-voice-cloning`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/smallest-voice-clone.json and https://www.anchorterminal.com/api/v1/tools/soniox-voice-cloning.json

## Other comparisons with Smallest.ai Instant Voice Clone or Soniox Voice Cloning

- [Cartesia Voice Cloning API + MCP vs Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/cartesia-voice-cloning-vs-smallest-voice-clone.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 Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/elevenlabs-voice-cloning-vs-smallest-voice-clone.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 Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/fish-audio-voice-cloning-vs-smallest-voice-clone.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 Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/gradium-voice-cloning-vs-smallest-voice-clone.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 Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/hume-voice-cloning-vs-smallest-voice-clone.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 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)
- [MiniMax Voice Clone and Voice Design vs Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/minimax-voice-cloning-vs-smallest-voice-clone.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 Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/murf-voice-cloning-vs-smallest-voice-clone.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 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)
- [Resemble AI Voice Cloning API vs Smallest.ai Instant Voice Clone](https://www.anchorterminal.com/compare/resemble-ai-voice-cloning-vs-smallest-voice-clone.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 Speechify API Voice Cloning](https://www.anchorterminal.com/compare/smallest-voice-clone-vs-speechify-voice-cloning.md)
- [Smallest.ai Instant Voice Clone vs Ultravox Voice Cloning](https://www.anchorterminal.com/compare/smallest-voice-clone-vs-ultravox-voice-cloning.md)
- [Smallest.ai Instant Voice Clone vs VoiceStudio](https://www.anchorterminal.com/compare/smallest-voice-clone-vs-voicestudio.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