Minimalist cost graph with downward trend showing AI API savings on dark background
← Blog10 min read

The Real Cost of AI APIs in 2026 (And How to Cut It)

LR
LLM Router Team

If you're running LLM calls in production, you've probably had that moment. You open your provider dashboard, look at last month's bill, and think: "Wait, how much?" You're not alone. AI API costs have a way of sneaking up on you, especially when your app starts getting real traffic.

Here's the thing: most teams are overpaying by 50-80%. Not because the providers are ripping them off, but because they haven't thought critically about which model they're using for which task. It's like renting a Ferrari to drive to the grocery store. Fun, sure. Necessary? Absolutely not.

Let me break down what AI APIs actually cost in 2026, where the hidden expenses are, and five practical ways to cut your bill dramatically.

The Current Pricing Landscape

First, let's get oriented. AI API pricing is measured in tokens — roughly 0.75 words per token. Most providers charge separately for input tokens (your prompt) and output tokens (the model's response). Output is always more expensive because it requires more compute.

Here's what the major providers charge as of early 2026:

ModelProviderInput (per 1M tokens)Output (per 1M tokens)
GPT-4oOpenAI$2.50$10.00
GPT-4o-miniOpenAI$0.15$0.60
o3-miniOpenAI$1.10$4.40
Claude Opus 4Anthropic$15.00$75.00
Claude Sonnet 4Anthropic$3.00$15.00
Claude 3.5 HaikuAnthropic$0.80$4.00
Gemini 2.5 ProGoogle$1.25$10.00
Gemini 2.0 FlashGoogle$0.10$0.40
DeepSeek V3DeepSeek$0.27$1.10
Llama 3.3 70BGroq / Together$0.18$0.18

Look at those numbers. The spread between the most expensive option (Claude Opus 4 at $15/$75) and the cheapest (Gemini 2.0 Flash at $0.10/$0.40) is 150x on input and 187x on output. That's an absurd range. And for many tasks, the cheap model gives you perfectly good results.

The Hidden Costs Nobody Talks About

The per-token price is only part of the story. Here's what actually drives your bill up:

System prompts eat your budget silently. If your system prompt is 2,000 tokens and you send it with every request, that's 2,000 input tokens you're paying for every single call. At GPT-4o rates, 1 million requests with that system prompt costs $5,000 just for the system prompt alone. And most apps send it on every turn of a conversation.

Conversation history compounds fast. In a multi-turn chat, you resend the entire conversation history with each new message. By turn 10, you might be sending 5,000+ tokens of history per request. Your costs per conversation grow quadratically, not linearly.

Retries and fallbacks add up. Rate limited? Timeout? Retry with the same expensive model. If you're doing 3 retries on 5% of requests, that's an invisible 15% cost increase on those calls.

Over-generation wastes tokens. If you ask a model for a one-paragraph summary and it writes four paragraphs, you're paying for all four. Output tokens are the expensive ones, and models love to be verbose.

The "Free Tier" Reality Check

A lot of developers search for "free AI API" options, and they do exist — but let's be realistic about what you get:

  • OpenAI: No free tier for API access. Period. The ChatGPT free plan doesn't include API access.
  • Google Gemini: Generous free tier — 15 RPM on Gemini Pro, which is enough for prototyping but not production.
  • Anthropic: No free tier. You get $5 in credits when you sign up.
  • Groq: Free tier with rate limits. Great for testing open-source models like Llama 3.
  • Together AI: $1 free credit on signup. Open-source models at very low prices after that.

Free tiers are fine for development. For production, you need a real budget. But the good news is that budget can be way smaller than you think if you're smart about it.

5 Strategies to Cut Your AI Costs

Here's the playbook. These aren't theoretical — they're what production teams actually do.

1. Route Simple Tasks to Cheaper Models

This is the single biggest lever you have. If 40% of your requests are simple enough for a model that costs 16x less, you just cut 37.5% off your total bill. And that's a conservative estimate.

An LLM router does this automatically. It classifies each request and picks the cheapest model that meets your quality threshold. No code changes required — you point your existing OpenAI SDK calls at the router, and it handles model selection.

// Before: everything goes to GPT-4o
const client = new OpenAI({ apiKey: "sk-..." });

// After: router picks the optimal model per request
const client = new OpenAI({
  apiKey: "your-router-key",
  baseURL: "https://router.requesty.ai/v1",
});

// Same code, 60-80% lower costs
const response = await client.chat.completions.create({
  model: "router",
  messages: [{ role: "user", content: userMessage }],
});

The compounding effect is real. Teams that implement routing typically see their cost-per-request drop from something like $0.03 to $0.005-0.01. Over millions of requests, that's the difference between a $30k bill and a $7k bill.

2. Use Prompt Caching

If you send the same system prompt with every request (and you probably do), you're paying for it every single time. Prompt caching stores your system prompt server-side so you only pay for it once per session, not once per request.

Anthropic offers built-in prompt caching on their API. Routers like Requesty offer cross-provider caching that works regardless of which model handles the request. This alone can cut input token costs by 30-50% for conversational workloads with long system prompts.

3. Batch Non-Urgent Requests

Not everything needs a real-time response. Document processing, content generation, weekly reports — these can all be batched. OpenAI's Batch API gives you a 50% discount for requests that can tolerate up to 24 hours of latency. Anthropic offers something similar with their message batching.

If you've got a pipeline that processes documents overnight, batch it. There's no reason to pay real-time prices for async work.

4. Use Open-Source Models for the Right Tasks

Open-source models have gotten scary good. Llama 3.3 70B and DeepSeek V3 are competitive with GPT-4o on many benchmarks — at a fraction of the cost when hosted by providers like Groq or Together AI.

The math is striking. Llama 3.3 70B on Groq costs $0.18/1M tokens for both input and output. That's 55x cheaper on output compared to GPT-4o. For tasks like classification, summarization, and straightforward Q&A, the quality difference is negligible.

You don't have to go all-in on open source. Just use it where it makes sense, and save the expensive proprietary models for tasks that genuinely need them.

5. Set Up Smart Routing with a Quality Floor

This is the strategy that ties everything together. Instead of manually deciding which model to use for which task, set up a routing policy: "Use the cheapest model that scores above X on my quality criteria for this task type."

A well-configured router will:

  • Send simple queries to GPT-4o-mini or Gemini Flash ($0.10-0.15/1M input)
  • Route medium-complexity tasks to DeepSeek V3 or Claude Haiku ($0.27-0.80/1M input)
  • Escalate complex reasoning to GPT-4o or Claude Sonnet ($2.50-3.00/1M input)
  • Only use Opus-class models for genuinely difficult tasks that nothing else handles well

The result is that you're always paying the minimum necessary for the quality you need. No more, no less.

A Real Example: From $12k to $3.2k/Month

Here's a scenario based on real production workloads we've seen:

A SaaS company runs a customer support chatbot handling 500,000 requests/month. Before optimization, everything went through GPT-4o. Average cost: $0.024 per request. Monthly bill: ~$12,000.

After implementing routing with the strategies above:

  • 45% of requests (FAQ-type questions) routed to GPT-4o-mini — ~$0.001/request
  • 30% (standard support queries) routed to Claude 3.5 Haiku — ~$0.006/request
  • 20% (complex issues needing reasoning) kept on GPT-4o — ~$0.024/request
  • 5% (escalation-level problems) routed to Claude Sonnet 4 — ~$0.030/request
  • Prompt caching applied across all tiers — additional 25% savings on input tokens

New blended cost: ~$0.0064/request. Monthly bill: ~$3,200. That's a 73% reduction with no meaningful drop in customer satisfaction. The simple questions were already easy for any model. The hard ones still get the best models available.

What to Do Next

If you're spending more than a few hundred dollars a month on LLM APIs, the optimization opportunity is probably significant. Here's where to start:

  1. Audit your usage. Break down your requests by task type. How many are simple vs. complex? What's your average input/output token count?
  2. Test cheaper models. Take your 50 most common request types and run them through GPT-4o-mini, Claude Haiku, and DeepSeek V3. You'll be surprised how often the cheaper model is "good enough."
  3. Implement routing. Check out our router comparison to find a provider that fits your stack. Most can be set up in under an hour.
  4. Enable caching. If you're using system prompts (you are), enable prompt caching immediately. It's free money.
  5. Monitor and iterate. Track your cost per request over time. As new models launch and prices drop, your router will automatically take advantage.

The days of "just use GPT-4 for everything" are over. The models are too diverse, the price differences too large, and the routing tools too good. Your API bill should reflect the actual difficulty of what you're asking — not the price of the most expensive model in the catalog.

Browse our model pricing data to compare current rates across providers, or jump straight to the router comparison to start optimizing.