Which is cheaper, GPT-5.5 or Grok 4.3?

Grok 4.3. On a task of 1,500 input and 500 output tokens across 3 calls, Grok 4.3 costs $0.00938 per task against $0.06750 for GPT-5.5, which makes it 7.20x cheaper (a 86% saving).

How much do GPT-5.5 and Grok 4.3 charge per million tokens?

GPT-5.5: $5 per million input tokens and $30 per million output tokens. Grok 4.3: $1.25 input and $2.5 output. These are published list rates as of August 2026, excluding cached, batch and long-context tiers.

What does a million tasks cost on GPT-5.5 vs Grok 4.3?

At the same fixed profile, one million tasks cost $67,500 on GPT-5.5 and $9,375 on Grok 4.3. The gap comes entirely from list-price differences, not from any difference in the work done.

Model price comparisons · August 2026

GPT-5.5 vs Grok 4.3: API pricing compared

Same task, same tokens, two invoices. Every figure on this page is computed from our open pricing dataset, not copied from a blog post.

Grok 4.3 is 7.20x cheaper than GPT-5.5 on a realistic task profile of 1,500 input and 500 output tokens per call, 3 calls per task: $0.00938 against $0.06750 per task, a 86% saving on identical work. Run a million tasks a month and that is the difference between $9,375 and $67,500.

Model	Input $/1M tok	Output $/1M tok	Output multiple	$/task	$/1M tasks
GPT-5.5OpenAI · frontier	$5	$30	6x	$0.06750	$67,500
Grok 4.3xAI · mid	$1.25	$2.5	2x	$0.00938	$9,375

Monthly bill at three volumes

Tasks / month	GPT-5.5	Grok 4.3	Gap
10,000	$675	$94	$581
100,000	$6,750	$938	$5,813
1,000,000	$67,500	$9,375	$58,125

Where the money goes on each

GPT-5.5 prices output at 6x its input rate, so on this profile output is 67% of its task cost. Grok 4.3 prices output at 2x input, putting output at 40% of cost. The model with the higher output multiple rewards capping response length more; the one with the higher input share rewards prompt caching and context trimming more. Cost tells you nothing about quality: run both on twenty of your real cases before deciding, and treat the cheaper model as the default until it demonstrably fails.

Break-even against a dedicated GPU

Against a $2/hour dedicated instance ($1,460/month fixed), self-hosting overtakes GPT-5.5 at 21,630 tasks per month and overtakes Grok 4.3 at 155,733 tasks per month. The full method is in the self-hosting break-even guide.

Pricing the self-hosted side? Compare on-demand GPU rates:

Compare GPU cloud pricing →

Plug your own token counts into the $/task calculator, or read the full ten-model pricing comparison.

Compare against other models

Frequently asked

Which is cheaper, GPT-5.5 or Grok 4.3?: Grok 4.3. On a task of 1,500 input and 500 output tokens across 3 calls, Grok 4.3 costs $0.00938 per task against $0.06750 for GPT-5.5, which makes it 7.20x cheaper (a 86% saving).
How much do GPT-5.5 and Grok 4.3 charge per million tokens?: GPT-5.5: $5 per million input tokens and $30 per million output tokens. Grok 4.3: $1.25 input and $2.5 output. These are published list rates as of August 2026, excluding cached, batch and long-context tiers.
What does a million tasks cost on GPT-5.5 vs Grok 4.3?: At the same fixed profile, one million tasks cost $67,500 on GPT-5.5 and $9,375 on Grok 4.3. The gap comes entirely from list-price differences, not from any difference in the work done.