FutureAItechXFutureAITechX
Explore AI Tools
Category guide

AI APIs Compared

Developer platforms and inference providers compared on what their documentation actually states: per-token rates, context windows, free quotas and data retention. Prices are list prices and change often — every row links to its source and shows a verification date.

12 verified tools9 with a free plan12 with API access

The comparison at a glance

CriterionPerplexityStable Diffusion (Stability AI)Hugging FaceElevenLabsDeepL
ProviderPerplexity AIStability AIHugging FaceElevenLabsDeepL SE
What it is forAn AI answer engine that searches the web and cites sources, with access to models from several providers on paid plans.Stability AI's open-weight image models, also available through a credit-based API.Hub for sharing open models, datasets and demo apps, with paid compute for inference and hosting.Text-to-speech, voice cloning, transcription, music and voice agents from one platform and API.An AI translator for text, documents and speech, with a writing assistant and a developer API.
Latest confirmed model—Stable Diffusion 3.5 (image); Stable Audio 3.0 (audio, May 2026)
May 20, 2026		—Eleven v4
Sep 28, 2026		—
Main capabilities
  • Cited answers
  • Pro Search (Depends on plan)
  • Research (Deep Research) (Depends on plan)
  • Model Council (Depends on plan)
  • Brain (Preview)
  • Stable Diffusion 3.5 suite
  • Stable Image Ultra / Core API
  • Editing, upscaling and control APIs
  • Stable Audio 3.0
  • Stable Fast 3D
  • Model and dataset hub
  • Spaces
  • Inference Providers
  • Inference Endpoints
  • Team and Enterprise controls (Depends on plan)
  • Eleven v4 TTS
  • Voice cloning (Depends on plan)
  • Scribe speech-to-text
  • Eleven Music
  • ElevenAgents
  • Text and document translation (Depends on plan)
  • Glossaries (Depends on plan)
  • DeepL Write Pro (Depends on plan)
  • DeepL Voice (Depends on plan)
  • Translation memory (Depends on plan)
  • API
Free planYes
3 Pro Searches/day; 1 Research query/month; limited uploads		Yes
Organisations or individuals under $1M annual revenue		Yes
No included inference credits		Yes
10,000 credits/month (about 10 min TTS); 3 custom voice slots; 3 Studio projects		Yes
50,000 characters per user/month; 1 file translation/month (5 MB max); 1 glossary (5 entries per language pair)
Cheapest paid planEducation Pro: $10/mo
With SheerID student verification		No monthly list pricePRO: $9/moStarter: $6/mo
$5/mo billed annually
Promo first-month prices may apply		No monthly list price
API accessYes · docs (opens in a new tab)Yes · docs (opens in a new tab)Yes · docs (opens in a new tab)Yes · docs (opens in a new tab)Yes · docs (opens in a new tab)
Learning curveBeginner-friendlyTechnicalSome experience helpsBeginner-friendlyBeginner-friendly
Last verifiedOct 19, 2026Oct 23, 2026Oct 19, 2026Oct 23, 2026Oct 19, 2026

Browse genuinely free AI tools Browse the full directory

How we would choose

  • Compare per-token rates for the model you will actually call, not the cheapest model on the page.
  • Free quotas are real but small — design for the paid rate from day one.
  • Data-retention and training terms differ sharply between consumer and API surfaces.

Advantages

  • One integration unlocks a whole model family and upgrade path
  • Structured outputs, tool calling and batch endpoints are documented
  • Competitive pressure keeps list prices falling — re-check quarterly

Limitations

  • Token costs surprise teams that skip estimation for their real workload
  • Rate limits and regional availability vary
  • Vendor lock-in through SDK-specific features is real

Practical use cases

Illustrative scenarios for this category — not customer case studies.

  • Routing production traffic between models by cost and capability
  • Structured decision endpoints for approvals and triage
  • Batch document processing with cached inputs to cut costs

Frequently asked questions

How is API pricing calculated?
Per million tokens, usually split input and output. The table links each provider's official pricing page and shows when we verified it.
Do any APIs have a free tier?
Some document free quotas or trial credits — the free-API-quota row states what is documented, and it is rarely enough for production.
Which provider should we start with?
Start with the provider whose models you evaluated on your own tasks, then add a second provider for routing — the directory documents both.
Is our API data used for training?
API terms generally differ from consumer terms — check each provider's retention documentation, linked from the comparison.

Also in this category

OpenAI API

Pay-per-token developer access to OpenAI's GPT models for building apps, agents and automations.

OpenRouter

One OpenAI-compatible API key for hundreds of models from many providers.

Together AI

Cloud platform for running, fine-tuning and training open models on serverless APIs or rented GPUs.

GroqCloud

Low-latency inference API for open models running on Groq's LPU hardware.

Ollama

Open-source tool for running open models on your own computer, with optional paid cloud models.

Related comparisons and guides

AI model APIs compared side by sideVerified data from the same directory.AI coding tools comparedVerified data from the same directory. The full AI tools directorySearch, filter and compare every verified tool.

The table shows up to five entries in the directory's editorial order, not a ranking. Every value links back to a record with sources and a last-verified date.