OpenAI vs xAI: Token Pricing, Speed & Intelligence
Full comparison of OpenAI and xAI — live token pricing, latency, throughput, context window, strengths, weaknesses, and best use cases. Updated July 2026.
OpenAI
GPT-4o, o3, and the world's most widely-used AI API
OpenAI is the creator of the GPT model family and the ChatGPT product. Their API provides access to frontier models including GPT-4o, the o-series reasoning models, and the GPT-4.1 long-context family. Pricing is competitive for frontier-tier capability, with prompt caching available on most models.
xAI
Grok 3 — Elon Musk's frontier AI with real-time web access
xAI is Elon Musk's AI company, building the Grok model family. Grok 3 is a frontier-tier model with a 131K context window and strong vision capabilities. Grok 3 Mini is a cost-efficient reasoning model. The API is available via the xAI platform with competitive frontier pricing.
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Live token pricing
Strengths & weaknesses
OpenAI
xAI
Key differentiators
Frequently asked questions
OpenAI FAQs
How much does the OpenAI API cost?
GPT-4o costs $2.50/1M input tokens and $10/1M output tokens. GPT-4o-mini is $0.15/$0.60 per 1M tokens. Prompt caching cuts input costs by 50% on eligible requests.
What is the difference between GPT-4o and o3?
GPT-4o is a fast, multimodal model optimised for chat, vision, and coding. o3 is a reasoning model that uses chain-of-thought to solve complex problems — it is slower and more expensive but significantly more capable on math, science, and hard coding tasks.
Does OpenAI support prompt caching?
Yes. Prompt caching is available on GPT-4o, GPT-4.1, o3, and o4-mini. Cached input tokens are billed at 50% of the standard input price, making long-context and repeated-system-prompt workloads significantly cheaper.
xAI FAQs
What is Grok and how much does it cost?
Grok is xAI's family of frontier LLMs. Grok 3 costs $3/1M input and $15/1M output tokens. Grok 3 Mini is a cheaper reasoning model at lower price points. Both support vision and function calling.
Does Grok have real-time web access?
Yes. Grok models can access real-time web content and X/Twitter data, making them uniquely suited for applications that need current information beyond a training cutoff.
How does Grok 3 compare to GPT-4o?
Grok 3 is competitive with GPT-4o on most benchmarks with strong vision capabilities. Its main differentiator is real-time web and X/Twitter data access. Pricing is similar to GPT-4o.