GPT-5.5 vs Grok 4: token pricing & cost compared (July 2026)

How GPT-5.5 (OpenAI) and Grok 4 (xAI) actually compare on price — input, output, and total monthly cost at the MAU you care about. Updated against live OpenRouter pricing.

OpenAI

GPT-5.5

Input: $5.00 / 1M tokens
Output: $30.00 / 1M tokens
Output / Input ratio: 6.0×
Context window: 1,050K

xAI

Grok 4

Input: $0.00 / 1M tokens
Output: $0.00 / 1M tokens
Output / Input ratio: —
Context window: —

The short answer

Grok 4 is cheaper across the board for typical workloads.

Token pricing side-by-side

GPT-5.5
Grok 4

Cost at your usage

Avg input tokens / call

Avg output tokens / call

Calls per active user / day: 5

Active days / month: 20

MAU: 1,000

GPT-5.5

Per call

$0.01750

Per user / mo

$1.7500

Total / mo

$1,750

Grok 4

Per call

$0.00000

Per user / mo

$0.0000

Total / mo

Grok 4 is cheaper by $1.7500/user/month — a saving of $1,750/month at 1,000 MAU.

Total monthly bill across MAU

GPT-5.5
Grok 4

Same usage profile applied to both models; only the per-token price differs.

Run this against your real numbers

The mini-calculator above is a preview. Use the full tools to model power-user blast radius, gross margin, and 12-month spend forecasts.

Other comparisons

Claude Opus 4.8 vs GPT-5.5 GPT-5.5 vs Claude Opus 4.7 GPT-5.5 vs Gemini 3.1 Pro Claude Opus 4.7 vs Grok 4 Gemini 3.1 Pro vs Grok 4 Fable 5 vs GPT-5.5

Comparing GPT-5.5 vs Grok 4 on price alone never tells the whole story — output-token weighting, context length, and your usage profile change the answer dramatically. Use the calculators below for the full picture.