OpenAI-compatible API · free models only
An OpenAI-compatible API that routes every request to the best free model available right now. Change two lines of code. Pay once.
7-day free API key · 100 calls/day · no card · then $49/year or $99 once
POST /api/v1/chat/completions
Live# Two lines. That's the whole integration.
client = OpenAI(
base_url="https://www.zerolimitai.com/api/v1",
api_key="YOUR_KEY",
)
client.chat.completions.create(
model="auto", messages=[...]
)Routing chain right now
When a model rate-limits, the next one answers. The response tells you which.
A free key, two settings in Cline, one request, and what happens when the top model is busy.
Anything that speaks the OpenAI format and lets you set a base URL works unchanged. No plugin, no adapter.
What developers run on it
All six →Backend for your AI coding assistant
200 requests/day → $108/mo at GPT-4o list price · $0/mo here
Support bot for Telegram, Discord or your site
1,000 requests/day → $203/mo at GPT-4o list price · $0/mo here
Summarise documents in a pipeline
500 requests/day → $375/mo at GPT-4o list price · $0/mo here
API tiers
Our engine ranks every major free model daily and routes each request to the top performer that is answering right now.
Live · the first Active model answers, the rest are failover · re-ranked every 24h
Intelligence
Artificial Analysis index
Coding
Artificial Analysis index
Agentic tasks
Tool use, multi-step work
Human preference
LM Arena votes
Instruction following
LM Arena category
Context window
32k tokens or more
Answer length
Max output tokens
Tools & JSON
Function calls, structured output
Latency
Time to first word, measured by us
Reliability
Our own failure rate
Daily auto-ranking
Models ranked every 24h so you always get the current best
Smart failover
If a model is down, the next best one responds instantly
Zero config
No need to choose a model — we handle it automatically
Live · no signup
Ask anything, no account needed. It's the chat that comes with Lifetime, on the same router as the API.
Try it now — no signup required
↵ Enter to send · Shift+Enter for new line
Powered by ZeroOptimize™ —auto-picks the best model · No signup needed
No per-token meter. $49 a year — or $99 once, for good. Both cover the API and the app.
Prices in USD · VAT may apply
App 3 days · API 7 days · no credit card
Everything in Lifetime, billed yearly
Developer API · 2,000 calls/day
Then your own Groq or OpenRouter key, with no limit of ours.
Everything, forever — API included
Launch price. When early access ends, the Lifetime price goes up or the plan closes, with 14 days' notice by email. What you buy now stays yours.
Developer API · 5,000 calls/day
OpenAI-compatible. Change two lines, keep your code.
Then your own Groq or OpenRouter key, with no limit of ours.
Unlimited chat, forever
Unlimited chat, 5,000 API calls a day, no monthly fee.
Just want the app? Chat, images and agents, no API: $19/year →
30-day money-back guarantee · No monthly fees · Your data is never used for training
A paid plan isn't only the API: chat, agents with memory (ZeroClaw) and image generation — all on the same routing.
Unlimited messages, best model, every time
Free Sana model, up to 100/day
Full code generation, review and debugging
Upload images, get instant AI analysis
PDF, TXT, CSV, MD and more
Real-time web results in every chat
Your personal AI agent
Unlike a chatbot, ZeroClaw builds memory about you and gets smarter with every conversation.
Works with OpenClaw
Use ZeroLimitAI as AI backend in OpenClaw, Cursor, Continue, or any OpenAI-compatible app.
baseURL: zerolimitai.com/api/v1
apiKey: zlai_••••••••••
Reference workload: a support bot answering 1,000 requests a day (1,500 tokens in, 300 out). List prices as of 2026-09.
| Option | Cost for that workload | Which model answers | When a model rate-limits or goes down |
|---|---|---|---|
| Paid API, per token | $12/mo on GPT-4o mini · $203/mo on GPT-4o | The one you pay for | Rare. You pay for that reliability on every token. |
| One free provider, direct | $0 | The one you hard-coded | Your app stops until you notice and switch. Free tiers rate-limit hard and models get withdrawn. |
| Your own router over free models | $0 + your time | Whatever your ranking says | Handled, if you built health checks, fallback and re-ranking, and keep them current. |
| ZeroLimitAI | $0/mo · $99 once | The best free model right now, re-ranked daily | The next model in the chain answers the same request. You see which one in the response. |
Paid API, per token
$12/mo on GPT-4o mini · $203/mo on GPT-4o
The one you pay for
Rare. You pay for that reliability on every token.
One free provider, direct
$0
The one you hard-coded
Your app stops until you notice and switch. Free tiers rate-limit hard and models get withdrawn.
Your own router over free models
$0 + your time
Whatever your ranking says
Handled, if you built health checks, fallback and re-ranking, and keep them current.
ZeroLimitAI
$0/mo · $99 once
The best free model right now, re-ranked daily
The next model in the chain answers the same request. You see which one in the response.
When we are the wrong choice
If the job needs one specific paid frontier model, a guaranteed quantisation of it, or embeddings today, use a paid API: we route to free models only, and the endpoint covers chat completions, streaming and function calling. If the job runs well on the best free model, there is no reason to keep a per-token meter running.
See six workloads with the mathsCheck it yourself
Comparing chat subscriptions instead? ChatGPT Plus · Claude Pro · Gemini Advanced · Grok · Perplexity Pro
Costs are computed from public list prices and the stated volume, not from customer data.
Yes, for chat completions. POST /api/v1/chat/completions takes the same request body and returns the same response shape, streaming included, with OpenAI-format errors and X-RateLimit headers. The official SDKs, LangChain, Cline, Continue and Aider work by changing base_url and api_key. Function calling (tools) works too, routed to the free models that support it. Embeddings are not supported yet.