AI21 alternatives

Tools that do what AI21 does, found by what they say they do rather than by shelf. Among the equally alike, the most used come first. Each line says how it differs from AI21.

Read 2026-10-17 · AI21 itself: Free plan · From $0.20 per use

With a free plan or free to use: Fireworks AI, FastRouter.ai, LiteLLM, LLM Gateway Chat, Truefoundry, Septor Labs, Inferbase, RunInfra, OpenRouter.

10 alternativesUnlike AI21

#1
Fireworks AI LLM operations
Routes requests to open or closed language models and trains specialized models on your data.
CheaperAlso: Fine-tuning, RAG
8.7k
Active
From $0.01 per use
#2
FastRouter.ai LLM operations
Routes requests across 200+ LLMs through a single OpenAI-compatible API with intelligent failover and cost optimization.
Same job
319
Active
From $199/mo
#3
LiteLLM LLM operations
Routes requests across 140+ LLM providers and 1800+ models through a single API gateway with cost optimization and access controls.
Can run on your serversNewer, since 2023
15.2k
Active
Free plan
2023
#4
LLM Gateway Chat LLM operations
Routes requests across 40 LLM providers through a unified API with cost tracking and automatic failover.
Costs more
989
Active
From $5 per use
#5
Truefoundry LLM operations
Routes requests to language models and agents with observability, access controls, and deployment across cloud or on-premises infrastructure.
Also: AgentsCan run on your servers
46.2k
Active
From $25/user/mo
#6
Septor Labs LLM operations
Routes requests across language models, embeddings, and agents through a single OpenAI-compatible endpoint with caching and observability.
Also: AnalyticsNewer, since 2025
17
Active
From $14/mo
2025
#7
Inferbase LLM operations
Routes requests across language models, enforces policies, and logs every decision.
Same job
16
Active
Free plan
#8
RunInfra LLM operations
Serves open-source language models with prompt caching to reduce inference cost and latency.
CheaperAlso: Agents, RAG
5
Active
From $0.05 per use
2024
#9
AI Operator by BLACKBOX AI LLM operations
Routes prompts across hundreds of open and closed models through one encrypted, zero-retention endpoint, with an API for coding agents.
Costs moreAlso: Agents, Security
58.6k
Active
From $0.30 per use
#10
OpenRouter LLM operations
Routes API requests to 500 language models across 80 providers through a unified interface.
More widely usedNewer, since 2023
224k
Active
From $5.50/mo
2023

← AI21: the full card All LLM operations tools →

How this list is made: the words AI21 is described with (what it does, for whom, what it is used for) are matched against every tool in the Atlas. A tool on the same shelf, or doing the same kind of work, counts for a little more. Nothing here is paid for.