Cloud text-to-speech / AI voice service (freetts.org) offering neural voices across 75+ languages via a small REST/JSON API, plus speech-to-text, AI video and voiceover, audiobook generation, an SRT subtitle surface, and first-party Chrome, Edge and Firefox extensions. Built and operated by Outline Technologies (outline.ad), bootstrapped, founded 2025, hosted on Hetzner in Falkenstein DE behind Cloudflare. The API is a proxy over third-party neural TTS: the live GET /api/voices catalogue probed 2026-08-28 returned 1,410 voices across 152 locales sourced from Google (788), Microsoft Edge (318) and Microsoft Azure (304), of which the 318 Edge voices are the free tier. FreeTTS publishes no OpenAPI, no apis.json, no MCP server and no agent card.
FreeTTS is listed with 1 API on the APIs.io network. Tagged areas include Text-to-Speech, Speech Synthesis, AI-voice, Audio, and Media.
FreeTTS’s developer surface includes pricing, signup flow, support, engineering blog, and 12 more developer resources.
Regulatory Posture applies to this provider. Its tags matched the
AI & Biometrics regime, so
Regulatory Posture carries 15 points of the composite.
If this regime is wrong for your business, say so on your
provider repo — the
applicability map is public and we will correct it.
Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for
this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero:
never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and
several others — scorable at all.
The six quality facets above are damped to 85 points between them,
because the conditional facet above carries the other
15. That is why each facet's contribution is shown against a damped
maximum: raising a quality facet moves the composite by 85% of its nominal
weight, not 100%. The full arithmetic is at apis.io/rating/.
Show this score on your site.
It updates itself when the score changes. Paste this where you link to your API docs:
<a href="https://apis.io/providers/freetts/"><img src="https://apis.io/badge/freetts/card.svg" alt="FreeTTS on APIs.io — Kin Score by API Evangelist"></a>
Other styles, a README pill and a shields.io endpoint are on the badge page.
Raise your score.
Agent readiness — checks not met, largest first (exact, from this profile):
Idempotency+9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card+8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples+7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
10 more unmet checks in the Agent Readiness table above.
Kin Score — facets with the most composite points still available (weight × headroom):
The Kin Score Market layer reads a provider inside its market:
its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted:
not part of the Kin Score or agent readiness.
Registered MCP server and declares compatibility are report only — not weighted.
Undeclared means we found nothing we can read, so there is no number: we never infer integrations.
REST/JSON API for text-to-speech synthesis, audio and SRT subtitle download, and voice listing. Uses x-api-key header auth. Endpoints: POST /api/v1/tts, GET /api/audio/{file_id}...
name: FreeTTS
aid: freetts
description: 'Cloud text-to-speech / AI voice service (freetts.org) offering neural voices across 75+ languages via a small
REST/JSON API, plus speech-to-text, AI video and voiceover, audiobook generation, an SRT subtitle surface, and first-party
Chrome, Edge and Firefox extensions. Built and operated by Outline Technologies (outline.ad), bootstrapped, founded 2025,
hosted on Hetzner in Falkenstein DE behind Cloudflare. The API is a proxy over third-party neural TTS: the live GET /api/voices
catalogue probed 2026-08-28 returned 1,410 voices across 152 locales sourced from Google (788), Microsoft Edge (318) and
Microsoft Azure (304), of which the 318 Edge voices are the free tier. FreeTTS publishes no OpenAPI, no apis.json, no MCP
server and no agent card.'
url: https://raw.githubusercontent.com/api-evangelist/free-tts/refs/heads/main/apis.yml
deliveryModel:
model: saas
open_source: false
commercial: true
callable_host: false
label: Hosted service · you call their endpoint
confidence: medium
source:
- pricing
generated: '2026-08-28'
method: derived
accessModel:
pricing: freemium
onboarding: self-serve
trial: false
try_now: true
public: false
gated: none
gated_source:
- onboarding
label: Freemium · Self-serve signup
confidence: high
source:
- plans
- authentication
- rate-limits
- security
generated: '2026-11-02'
method: derived
created: '2026-08-28'
modified: '2026-08-28'
specificationVersion: '0.21'
image: https://freetts.org/images/og-image.webp
tags:
- Text-to-Speech
- Speech Synthesis
- AI-voice
- Audio
- Media
- Accessibility
- Speech-to-Text
- Content Creation
- Developer Tools
tags_raw:
- Text-to-Speech
- Speech Synthesis
- AI Voice
- Audio
- Media
- Accessibility
- Speech-to-Text
- Content Creation
- Developer Tools
apis:
- name: FreeTTS REST API
description: 'REST/JSON API for text-to-speech synthesis, audio and SRT subtitle download, and voice listing. Uses x-api-key
header auth. Endpoints: POST /api/v1/tts, GET /api/audio/{file_id}, GET /api/srt/{file_id}, GET /api/voices.
Submitted 2026-08-28 from shubham@telenow.ai with a NAME ONLY -- no apis.json, no docs URL, no provider. telenow.ai is
a HubSpot page unrelated to freetts.org, and nothing on freetts.org links the two, so this is a third-party submission.
freetts.org itself is healthy and serves an llms.txt; no apis.json and no OpenAPI resolve. The gate''s own research notes
the backend proxies Microsoft Azure Neural TTS -- recorded as provenance, not as a policy problem: building a product
on Azure TTS is that service''s intended use, unlike the model relays refused this week, which documented redirecting
first-party CLI clients. Verified 2026-08-28.
ENRICHMENT PASS 2026-08-28: contract discovery ran against the API host root, the docs host and every well-known path
and found no machine-readable contract. /openapi.json, /swagger.json, /openapi.yaml, /api-docs, /docs and /redoc all return
the Next.js catch-all 404; /api/openapi.json, /api/v1/openapi.json, /api/docs, /api/redoc and /api/schema all return the
API application''s own JSON 404 {"detail":"Not Found"}, so the FastAPI-style app that serves this API has its interactive
docs and schema routes disabled. No GraphQL, no MCP endpoint, no agent card, no WSDL, no .proto. The endpoint set is larger
than first recorded: POST /api/v1/tts, POST /api/tts-pro (expressive styles, named only in llms.txt, existence confirmed
by a live 405 on GET), GET /api/audio/{file_id}, GET /api/srt/{file_id}, GET /api/voices and an undocumented GET /api/health
returning 200 {"status":"ok","timestamp":<epoch>}. GET /api/voices is fully open - it returned 585,024 bytes and 1,410
voice objects with no credential. The /developers hero markets the API as "No Key Required" while the same page''s FAQ,
all four code samples and the live 401 ({"detail":"Missing x-api-key header"}) require an x-api-key header. Free-tier
limits are published at three different values (10, 15 and 20 requests/minute) and the per-request character cap at two
(1,000 and 5,000) across two of the provider''s own pages, and no rate-limit response headers are emitted at all. The
documented embed widget loader https://freetts.org/widget.js returns 404.'
humanURL: https://freetts.org/developers
baseURL: https://freetts.org/api
tags:
- Text-to-Speech
- Speech Synthesis
- AI-voice
- Audio
- Media
- Accessibility
- Speech-to-Text
- Content Creation
- Developer Tools
tags_raw:
- Text-to-Speech
- Speech Synthesis
- AI Voice
- Audio
- Media
- Accessibility
- Speech-to-Text
- Content Creation
- Developer Tools
properties:
- type: Documentation
url: https://freetts.org/developers
- type: APIReference
url: https://freetts.org/developers#endpoints
- type: GettingStarted
url: https://freetts.org/developers#quickstart
- type: LLMsTxt
url: https://freetts.org/llms.txt
- type: Authentication
url: authentication/freetts-authentication.yml
- type: ErrorCatalog
url: errors/freetts-problem-types.yml
- type: RateLimits
url: rate-limits/freetts-rate-limits.yml
- type: Conventions
url: conventions/freetts-conventions.yml
- type: DataModel
url: data-model/freetts-data-model.yml
- type: JSONSchema
url: json-schema/freetts-voice.json
maintainers:
- FN: FreeTTS
url: https://freetts.org
email: info@freetts.org
generated:
by: apis.io/add
model: claude-opus-4-8
confidence: 85
at: '2026-08-28T07:30:05.533Z'
common:
- type: RateLimits
url: rate-limits/freetts-rate-limits.yml
- type: Website
url: https://www.freetts.org/
- type: DomainSecurity
url: security/freetts-domain-security.yml
- type: DeveloperPortal
url: https://freetts.org/developers
- type: Pricing
url: https://freetts.org/pricing
- type: SignUp
url: https://freetts.org/login
- type: TermsOfService
url: https://freetts.org/terms
- type: PrivacyPolicy
url: https://freetts.org/privacy
- type: Support
url: https://freetts.org/contact
- type: Blog
url: https://freetts.org/blog
- type: LLMsTxt
url: llms/freetts-llms.txt
- type: Packages
url: packages/freetts-packages.yml
- type: Plans
url: plans/freetts-plans-pricing.yml
- type: Lifecycle
url: lifecycle/freetts-lifecycle.yml
- type: Conformance
url: conformance/freetts-conformance.yml
- type: Components
url: components/freetts-components.yml
x-enrichment:
date: '2026-08-28'
status: enriched
artifacts_added: 15
pass: local-v1
FreeTTS API — frequently asked questions
Does FreeTTS have an API?
Yes. APIs.io lists 1 API from FreeTTS, including FreeTTS REST API.
How do I authenticate with the FreeTTS API?
FreeTTS uses bearer-token authentication (2 schemes). The details are profiled on APIs.io as Freetts Authentication.
How much does the FreeTTS API cost?
APIs.io lists 3 pricing plans for FreeTTS, with each plan's price, limits and inclusions under Pricing Plans on this page.
Is the FreeTTS API ready for AI agents?
FreeTTS has a Kin Score of 44.7 out of 100 (developing) and an Agent Readiness score of 7.9 (agent-aware), scored by API Evangelist on 2026-11-02.
Discovery needs no key. Ratings and market analysis are Pro.
Get an API key
Free tier, no form to fill in. Signing in shares your email address with us — we
store it to create your key and to recognise you if you sign in with another
provider. See our Privacy Policy and
Terms.
Kin Score
How this is scored →
It updates itself when the score changes. Paste this where you link to your API docs: