Connecting an AI agent to the right model backend is one of the most important decisions in your setup. The wrong choice means paying too much, waiting too long, or getting output quality that does not match your needs. Here is a practical comparison of every major option available in 2026.
Ollama (Local, Free)
What it is: A tool that runs open-weight models (Llama, Mistral, Qwen, DeepSeek, Phi) entirely on your machine. No API key needed, no cost per token, no data leaving your device.
Best models: Llama 3.1 8B (general use, 8GB RAM), Qwen 2.5 14B (strong on reasoning and code, 16GB RAM), Mistral 7B (fast, efficient), DeepSeek Coder (coding tasks specifically).
Quality: Excellent for everyday tasks — email drafting, summarisation, file management, Q&A on your own documents. Noticeably behind GPT-4o on complex reasoning, long-document analysis, and edge cases that require deep world knowledge.
Privacy: Perfect. Nothing leaves your machine.
Cost: $0 per query. Electricity cost is negligible.
Speed: 1-15 seconds per response depending on model size and hardware. GPU-accelerated machines (Apple Silicon, discrete Nvidia) are significantly faster than CPU-only.
Best for: Anyone processing sensitive data; users who want zero ongoing costs; offline operation; privacy-first workflows.
OpenRouter (Cloud, Pay-as-You-Go)
What it is: A unified API that gives you access to models from OpenAI, Anthropic, Google, Meta, Mistral, and many others under a single API key. You pay per token consumed, with no monthly subscription.
Quality: Access to GPT-4o, Claude 3.5 Sonnet, Gemini 1.5 Pro — the best models available. Also offers free-tier access to smaller open models.
Privacy: Your queries go to OpenRouter's servers and then to the underlying provider. OpenRouter has a no-training policy on API queries, but data does transit to third-party infrastructure.
Cost: Varies by model. GPT-4o: ~$5 per million input tokens. Claude 3.5 Sonnet: ~$3 per million input tokens. Budget models via free tier: $0. Typical moderate use: $3-10 per month.
Speed: 1-3 seconds for most queries. Consistent regardless of your hardware.
Best for: Getting access to multiple frontier models with one API key; pay-as-you-go flexibility; users who occasionally need the best available model but do not want multiple subscriptions.
OpenAI Direct (Cloud, Pay-as-You-Go or Subscription)
What it is: Direct API access to GPT-4o, GPT-4o mini, and OpenAI's o1/o3 reasoning models.
Quality: GPT-4o is among the best general-purpose models available. o1/o3 reasoning models are exceptional for complex mathematical and logical problems.
Privacy: Queries processed on OpenAI servers. Data retention depends on your API account settings — API usage is not used for training by default with an opt-out setting.
Cost: GPT-4o: $5/million input tokens. GPT-4o mini: $0.15/million tokens. More expensive than OpenRouter for the same models.
Best for: Users who specifically want OpenAI models and want the most direct relationship with the provider. Otherwise OpenRouter provides the same models at lower effective cost.
Anthropic Direct (Cloud)
What it is: Direct API access to Claude 3.5 Sonnet and Haiku.
Quality: Claude 3.5 Sonnet is widely regarded as the best model for writing quality, nuanced instruction-following, and long-document analysis. Haiku is fast and cheap for simpler tasks.
Cost: Claude 3.5 Sonnet: $3/million input tokens. Haiku: $0.25/million input tokens.
Best for: Writing-heavy workflows where output quality and tone matter most. Again, OpenRouter provides access to the same models.
Groq (Cloud, Fast Inference)
What it is: A cloud inference provider that runs open-weight models (Llama 3.1, Mistral, Gemma) on specialised hardware at very high speed.
Quality: Same models as Ollama, but running on Groq's LPU hardware which is much faster than most consumer machines.
Cost: Free tier available. Paid tier is low-cost.
Best for: Users with low-powered hardware who want fast inference on open-weight models without paying frontier model prices. Also excellent for Whisper speech transcription, where Groq's speed advantage is most pronounced.
The Recommendation Matrix
If you care about privacy above all else: use Ollama. If you want the best quality for general tasks: use OpenRouter with Claude 3.5 Sonnet or GPT-4o. If you want zero monthly costs: use Ollama plus OpenRouter free tier. If you have a slow machine and want fast open-weight inference: use Groq. If you want all of the above depending on the task: use Skales, which supports all of these providers simultaneously and lets you route tasks appropriately. See the full provider list in Skales or download free.