# Gradium Voice Cloning and Voice Design vs Speechify API Voice Cloning (slim)

> Speechify API Voice Cloning scores 76.9 (BB) to Gradium Voice Cloning and Voice Design's 60.8 (C) for voice cloning. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/gradium-voice-cloning-vs-speechify-voice-cloning.md (~5,900 tokens) · this version ~3,430 tokens · JSON https://www.anchorterminal.com/compare/gradium-voice-cloning-vs-speechify-voice-cloning.json · canonical https://www.anchorterminal.com/compare/gradium-voice-cloning-vs-speechify-voice-cloning
- 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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Speechify API Voice Cloning scores 76.9 (BB) on agent readiness against Gradium Voice Cloning and Voice Design's 60.8 (C), and leads in 6 of 7 scored categories. Gradium Voice Cloning and Voice Design leads on payments & pricing. Both do voice cloning.

- Gradium Voice Cloning and Voice Design: C 60.8, rank #637 of 1486 · https://www.anchorterminal.com/tools/gradium-voice-cloning.min.md
- Speechify API Voice Cloning: BB 76.9, rank #37 of 1486 · https://www.anchorterminal.com/tools/speechify-voice-cloning.min.md
- Gradium Voice Cloning and Voice Design, good for Builders on Gradium's TTS who want instant clones and designed voices in five European languages with EU residency. Ahead on Payments & pricing, 30 against 20. Also Free to start without a card; No incidents deducted, where Speechify API Voice Cloning loses 3 points for them.
- Speechify API Voice Cloning, good for Best where a consent record and a published destruction schedule for voice data matter, such as cloning staff or talent voices for a product. Ahead on Reliability, 90 against 63; Schema & documentation, 94 against 83; Agent ergonomics, 97 against 67; Security & auth, 87 against 48; Maintenance & community, 75 against 70; Transparency & trust, 75 against 63. Also Agent-ready, a grade of BB or better.

| Category | Gradium Voice Cloning and Voice Design | Speechify API Voice Cloning |
| --- | --- | --- |
| Reliability (16%) | 63 | 90 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 83 | 94 |
| Agent ergonomics (13%) | 67 | 97 |
| Security & auth (14%) | 48 | 87 |
| Payments & pricing (10%) | 30 | 20 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 70 | 75 |
| Transparency & trust (7%) | 63 | 75 |

| Fact (where they differ) | Gradium Voice Cloning and Voice Design | Speechify API Voice Cloning |
| --- | --- | --- |
| Vendor | Gradium SAS | Speechify |
| Hosted endpoint | `https://api.gradium.ai/api/voices/` | `https://api.speechify.ai/v1` |
| Transports | HTTP, websocket | HTTP |
| Pricing | Freemium | Paid |
| Price for voice cloning | not published | $6 per 1M characters |
| Licence | Proprietary service under Gradium's Terms of Service (version of 19 October 2026). The `gradium` Python SDK is on PyPI | MIT (SDKs) |
| Last release | 2026-11-06 | 2026-10-29 |
| Terms last updated | no date given | 2024-06-10 |
| Privacy policy last updated | no date given | 2026-07-22 |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | not found in the text | yes |
| Popularity | none | 3 stars, 1.9k npm/wk, 6.5k PyPI/wk |
| Agent reviews | none | 3.6/5 (8) |

Why the edge:
- Security & auth, Speechify API Voice Cloning +39: Gradium Voice Cloning and Voice Design 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. API keys per organisation in a header, revocable and able to expire, with no scopes found (20 of 30). No consent or verification field and no watermark. The Terms make the client obtain the consent of anyone whose voice is a sample and bar impersonation without explicit authorisation, and the API FAQ says explicit consent is required (6 of 20). The Terms grant Gradium a licence to use Client Data to improve its services and train its models, with no opt-out found, and zero data retention (paid plans) excludes voice samples, so samples are kept and may be used for training (2 of 15). Organisation roles and a member list, with no per-call audit log found (5 of 15). SOC 2 Type II and ISO 27001:2022 audited by A-LIGN, a trust centre and security@gradium.ai. No security.txt (404) and no bug bounty found (15 of 20). 20+6+2+5+15 = 48.); Speechify API Voice Cloning 87 (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. Service-account keys with scopes (`voices:read`, `voices:write`, `audio:all`), rotation with a grace window, and minted child keys capped at 24 hours (30). Every clone needs a single-use consent challenge, the speaker reads the phrase, and the create call is refused unless the words and speaker match, plus output watermarking with a detection endpoint (20). The trust page says Speechify never trains on customer data. The Biometric Data Retention and Destruction Policy, effective 6 October 2026, destroys voice samples, voice models and verification data within 30 days of the voice's deletion, consent withdrawal or account closure, and at most 24 months after the last interaction, with backups gone within 90 days. Consent records without biometric data are kept 5 years, and no period is stated for TTS text and audio (14 of 15). Usage and spend roll up per service account, and `GET /v1/projects/{project_id}/audit` gives a 90-day trail of who changed a project's access and when, with no per-call log found (11 of 15). security.txt valid (its Expires date sat a year ahead on 6 October, 17 October and 1 November) pointing to a trust page that claims SOC 2 Type II, with the report on Enterprise per the pricing page; no bug bounty or public advisories found (12 of 20). 30 + 20 + 14 + 11 + 12 = 87.)
- Agent ergonomics, Speechify API Voice Cloning +30: Gradium Voice Cloning and Voice Design 67 (Voice objects are compact metadata (20 of 25). `GET /voices/` takes `skip` and `limit` (default 100) and since 23 October filters by `locale`, `gender` and `use_case` (20). Validation errors are structured 422 bodies, while synthesis errors arrive as plain-text HTTP 500 with a numeric code to parse (12 of 20). No idempotency key. Saving a design candidate twice answers 409, and the clone call has none (5 of 20). Three required fields with sensible defaults, and one official SDK, in Python (10 of 15). 20+20+12+5+10 = 67.); Speechify API Voice Cloning 97 (Creating a voice returns a compact voice object, and `GET /v1/voices` takes `type=personal` to list only the workspace's clones (25). Voice lists page by `cursor` with `limit` up to 200 and the `type` filter (20). Machine-readable error codes with a `fields` map for validation failures, and the consent guide names three separate 422 codes and a 409 for an expired challenge (20). `Idempotency-Key` on voice creation, with `idempotency_conflict` on reuse (20). Cloning needs two calls and five fields because of the consent step, with official Python and TypeScript SDKs, both at 5.0.0 since 29 October (12 of 15).)
- Reliability, Speechify API Voice Cloning +27: Gradium Voice Cloning and Voice Design 63 (Graded on the hosted voice API with the hosted lines. Atlassian Statuspage at gradium.statuspage.io with five components, one of them Voice Cloning (20). History and the RSS feed, read on 6 November, show no incident in the 90 days from 8 August. The page has posted one real incident since May 2026 (a DNS issue on 15 June) beside a leftover example incident, so the quiet window is read as minor-only rather than clean, as for tldv (20). Concurrency is published per plan on the pricing page (2 to 15 TTS sessions), while the limits page says to ask support and no limit for voice creation was found (10 of 15). No 429, Retry-After or backoff guidance was found; the errors page says to open a new connection after an error, and voice creation takes a `timeout_s` (3 of 15). No SLA in the Terms or on the pricing page (0). Instant cloning carries no beta label (10). 20+20+10+3+0+10 = 63.); Speechify API Voice Cloning 90 (Status page at status.speechify.ai (Better Stack) with an API component (20). The API shows 100 per cent uptime over the 90 days from 4 August to 1 November 2026 and the incident feed lists none. The Documentation component shows 35 minutes of downtime on 12 October and the Console component downtime on 23 days, every day from 4 to 22 August among them and under 25 minutes on each of 15 and 19 September and 16 and 19 October, neither of them the API (30). Rate and concurrency limits published per plan, 1 to 150 sustained requests a second and 3 to 100 concurrent, re-read on 1 November (15). 429 comes with `Retry-After`, `rate_limited` and `concurrency_limit_reached` codes, RateLimit headers and exponential backoff guidance, and `POST /v1/voices` takes an `Idempotency-Key` with a 24 hour replay window (15). No SLA found (0). Cloning is generally available (10). 20 + 30 + 15 + 15 + 0 + 10 = 90.)
- Transparency & trust, Speechify API Voice Cloning +12: Gradium Voice Cloning and Voice Design 63 (Closed service with clear terms, version of 19 October 2026, naming Gradium SAS with its Paris registration (15 of 30). The Terms allow training on Client Data, zero data retention excludes voice samples, the privacy policy gives retention criteria without periods, and a DPA is published as an exhibit. The statements agree but give no retention period for samples (15 of 30). Deprecations appear in dated release notes, with no written notice policy (10 of 20). EU and US residency is documented and selectable from the XS plan. Sub-processors sit in the trust centre, not read (12 of 20). 15+15+10+12 = 52.); Speechify API Voice Cloning 75 (Closed service with clear API terms, SDKs under MIT (15 of 30). Terms (10 June 2024) and the trust page say customer data isn't used for training. The biometric data policy of 6 October 2026 sets destruction periods for voice samples, voice models and verification data, 5 years for consent records and 90 days for backups, and names service providers only by role. No public DPA (a custom DPA is listed on Enterprise), no subprocessor list and no period for TTS inputs and outputs were found (18 of 30, as for spider-cloud's stated periods with no public DPA). The September consent change was announced on 13 August, 41 days ahead, Simba 1.6 was retired at version 2026-09-21 with a dated switch on 2026-11-21 (`simba-multilingual` then served by Simba 3.5), the legacy api.sws.speechify.com host has a dated end of 19 January 2027 with Deprecation and Sunset headers, and legacy headers have a stated end date in mid-2027 (20). The regions guide of 17 October says accounts, keys, voices, usage and logs stay in the United States on every host and synthesis runs in US East or the Netherlands. No subprocessor list found (10 of 20, as for modal-sandboxes' region disclosure without a list). 15 + 18 + 20 + 10 = 63.)
- Schema & documentation, Speechify API Voice Cloning +11: Gradium Voice Cloning and Voice Design 83 (Public OpenAPI 3.1 file at docs.gradium.ai/api-reference/openapi.json (25). llms.txt and Markdown pages (10). The guides say when to clone, design, enhance or localise a voice, and the custom-voice page explains the enhancement default and how to opt out (14 of 20). The clone body has `audio_file`, `name` and `language` required, a five-value language enum and typed defaults for `start_s`, `enhance` and `timeout_s` (14 of 15). curl and Python examples. The create call documents only 201 and 422, and the errors page covers synthesis, with plain-text 500 bodies (9 of 15). Routes carry no version, the OpenAPI file is 0.1.0, and release notes are dated per entry, newest 6 November 2026 (11 of 15). The API reference FAQ gives a 300-second session where the limits page says 3,000. 25+10+14+14+9+11 = 83.); Speechify API Voice Cloning 94 (OpenAPI 3.1 at docs.speechify.ai/openapi.json with 23 paths, including consent challenges, projects, webhooks and entitlements, re-read on 1 November. The WebSocket input stream added on 8 October isn't among the 23 paths (25). llms.txt per section, Markdown pages and a docs-search MCP server (10). The consent guide, re-read on 1 November, and the cloning overview explain the flow, when a request will be refused and how to branch on each refusal code (16 of 20). Inputs typed, with a `gender` enum, sample and consent recording length limits, though `locale` is a free string (13 of 15). Each endpoint lists its error codes and statuses, with examples (15). Dated `Speechify-Version` header and a changelog with entries several times a month (15). 25 + 10 + 16 + 13 + 15 + 15 = 94.)
- Payments & pricing, Gradium Voice Cloning and Voice Design +10: Gradium Voice Cloning and Voice Design 30 (No x402, MPP or L402 (0). Plan prices and credits are public, 1 credit a character for speech, with no dollar price per unit, as cartesia-voice-cloning is read. Creating a clone uses no credits in the docs (10). The free plan has 45,000 credits a month, 5 custom voices and Voice Design, and the site says no credit card is required. Commercial use starts on the $12 plan (20). Signup is a browser flow in Gradium Studio (0). 0+10+20+0 = 30.); Speechify API Voice Cloning 20 (No x402, MPP or L402 (0). Per-unit overage prices are public, re-read on 1 November, $10, $8 and $6 per million characters by plan on Simba 3.0 and 3.2, and Simba 3.5 lists at $20, $16 and $12, billed at the lower rates until 21 November 2026 (20). The Free plan can't clone and has no voice design (0). Signup is a human browser flow (0).)