OpenAI vs xAI (Grok) Pricing
OpenAI is cheaper than xAI (Grok) at the entry level: gpt-oss-20b costs $0.140 per 1M output tokens against $0.500 for Grok 3 Mini — 3.6× the price. On current flagships, OpenAI's GPT-5.6 costs $30.00/1M output against $6.00/1M for xAI (Grok)'s Grok 4.5. Prices are USD, current as of August 11, 2026.
Per-million-token pricing for OpenAI and xAI (Grok), with side-by-side flagship models, cheapest tiers, and context windows. Pricing data syncs weekly from a continuously-updated model catalog — last updated August 11, 2026.
Who wins on what
Cheapest input tokens
$0.03/1MOpenAI
gpt-oss-20b — $0.03/1M input
Cheapest output tokens
$0.14/1MOpenAI
gpt-oss-20b — $0.14/1M output
Longest context window
2.0MOpenAI
gpt-5.4 (>272K context length) — 2.0M input tokens
Lowest average output cost
$6.72/1MxAI (Grok)
Provider-wide average across 45 models
Largest model catalog
129 modelsOpenAI
More options to match cost vs capability
Cheapest cached input
$0.02/1MOpenAI
GPT-5.6 Luna — $0.02/1M cached read
Most reasoning models
12 modelsOpenAI
Models with dedicated reasoning / thinking support
Most vision models
13 modelsOpenAI
Models that accept image input
Side-by-side
OpenAI
Full OpenAI pricing →Cheapest input
$0.030
gpt-oss-20b
Cheapest output
$0.140
gpt-oss-20b
Longest context
2.0M
gpt-5.4 (>272K context length)
Avg output / 1M
$29.47
Across catalog
Cheapest cached input
$0.020
GPT-5.6 Luna
| Model | In/1M | Out/1M | Ctx |
|---|---|---|---|
| GPT-5.6 VisionReasoningToolsCache | $5.00 | $30.00 | 1.1M |
| GPT-5.6 Sol VisionReasoningToolsCache | $5.00 | $30.00 | 1.1M |
| GPT-5.6 Terra VisionReasoningToolsCache | $2.00 | $12.00 | 1.1M |
| GPT-5.6 Luna VisionReasoningToolsCache | $0.200 | $1.20 | 1.1M |
| GPT-Realtime-2.1 VisionReasoningToolsCache | $4.00 | $24.00 | 128K |
| gpt-oss-20b | $0.030 | $0.140 | 131K |
xAI (Grok)
Full xAI (Grok) pricing →Cheapest input
$0.200
Grok 4 Fast
Cheapest output
$0.500
Grok 3 Mini
Longest context
2.0M
Grok 4 Fast
Avg output / 1M
$6.72
Across catalog
Cheapest cached input
$0.200
Grok 4.20 (Non-Reasoning)
| Model | In/1M | Out/1M | Ctx |
|---|---|---|---|
| Grok 4.5 VisionReasoningToolsCache | $2.00 | $6.00 | 500K |
| Grok 4.3 VisionReasoningToolsCache | $1.25 | $2.50 | 1.0M |
| Grok Build 0.1 VisionReasoningToolsCache | $1.00 | $2.00 | 256K |
| Grok 4.20 (Non-Reasoning) VisionToolsCache | $1.25 | $2.50 | 1.0M |
| Grok 4.20 (Reasoning) VisionReasoningToolsCache | $1.25 | $2.50 | 1.0M |
| Grok 3 Mini | $0.300 | $0.500 | 131K |
All prices in USD per 1 million tokens. Showing top 6 models per provider, sorted by output cost.
Frequently asked questions
Is OpenAI or xAI (Grok) cheaper?
OpenAI has the cheaper entry point at $0.14/1M output (gpt-oss-20b — $0.14/1M output). Provider-wide, OpenAI averages $29.47/1M output against $6.72/1M for xAI (Grok). Which is cheaper for you depends on which model tier your workload actually needs.
How much do OpenAI and xAI (Grok) cost per 1M tokens?
OpenAI starts at $0.140 per 1M output tokens (gpt-oss-20b), with its current flagship GPT-5.6 at $30.00. xAI (Grok) starts at $0.500 (Grok 3 Mini), with Grok 4.5 at $6.00. Input tokens cost less than output on both.
Which has the larger context window, OpenAI or xAI (Grok)?
OpenAI — gpt-5.4 (>272K context length) — 2.0M input tokens. For comparison, OpenAI's largest is 2.0M tokens (gpt-5.4 (>272K context length)) and xAI (Grok)'s is 2.0M tokens (Grok 4 Fast).
Which has more reasoning models, OpenAI or xAI (Grok)?
OpenAI lists 12 reasoning models and xAI (Grok) lists 5. Reasoning models bill their internal thinking as output tokens, so a reasoning call costs several times a standard completion of the same visible length — compare them on total tokens billed, not headline rate.
Should I switch from OpenAI to xAI (Grok) to save money?
Only if the cheaper model still meets your quality bar. Token price is one input; the ones that decide your bill are prompt size, response length, retries and how much conversation history you resend each turn. Model the switch against your real traffic before committing. Prices here are current as of August 11, 2026.
Related comparisons
Run the numbers for your workload
Calcaas multiplies per-token costs by your real usage patterns — inputs, outputs, retries, and conversation history — across both providers in one model.