API cost decision in 10 seconds

NewGrok 4.3 vs GPT-5.5 Pro

Pick Grok 4.3 for lower cost; pick GPT-5.5 Pro only if the larger context window matters more.

Pricing data updated: 2026-05-26T11:08:00Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Grok 4.3 for lower cost; pick GPT-5.5 Pro only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Grok 4.3 is estimated at $2.5 vs $120 for GPT-5.5 Pro, saving $117.5 (97.9% lower).

Cost-first pickGrok 4.3

Context-first pickGPT-5.5 Pro

Sample savings$117.597.9%

10x traffic gap$1175

GPT-5.5 Pro has more context, but Grok 4.3 saves $117.5 on the standard workload. At 10x that traffic, the same price gap is about $1175. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Grok 4.3 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Grok 4.3	GPT-5.5 Pro
Input-heavy / RAG	5M input + 500K output	Grok 4.3	$7.5	$240
Balanced workload	1M input + 1M output	Grok 4.3	$3.75	$210
Output-heavy chatbot	1M input + 5M output	Grok 4.3	$13.75	$930

Cheaper input Grok 4.3 $1.25 vs $30 / 1M

Grok 4.3 is $28.75 cheaper per 1M input tokens (95.8% lower; 24x difference).

Cheaper output Grok 4.3 $2.5 vs $180 / 1M

Grok 4.3 is $177.5 cheaper per 1M output tokens (98.6% lower; 72x difference).

Larger context GPT-5.5 Pro 1M vs 1.05M

GPT-5.5 Pro has 50K more context (1.05x larger).

Sample workload Grok 4.3 $2.5 vs $120

Grok 4.3 is $117.5 cheaper on the standard workload (97.9% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Grok 4.3 Calculating… Estimated API cost

GPT-5.5 Pro Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

Grok 4.3 has the lower input price; Grok 4.3 has the lower output price; GPT-5.5 Pro offers the larger context window. For the 1M input plus 500K output sample, Grok 4.3 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $2.5 for Grok 4.3 and $120 for GPT-5.5 Pro.

Best Fit

Choose Grok 4.3 when you care most about lower input-token price, and lower output-token price.

Choose GPT-5.5 Pro when you care most about larger context window.

Decision Notes

On the standard 1M input plus 500K output workload, Grok 4.3 is estimated at $2.5 vs $120 for GPT-5.5 Pro, saving $117.5 (97.9% lower).
Grok 4.3 is $117.5 cheaper on the standard workload (97.9% lower).
Grok 4.3 is $28.75 cheaper per 1M input tokens (95.8% lower; 24x difference).
Grok 4.3 is $177.5 cheaper per 1M output tokens (98.6% lower; 72x difference).
GPT-5.5 Pro has 50K more context (1.05x larger).

Head-to-Head Specs

Feature	NewGrok 4.3 (xAI)	GPT-5.5 Pro (OpenAI)
Input Price prompt tokens per 1M	$1.25	$30
Completion Price per 1M tokens	$2.5	$180
Sample Workload Cost 1M input + 500K output	$2.5	$120
Context Window	1M	1.05M
Release Date	2026-04-30	2026-04-24

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Grok 4.3	On the standard 1M input plus 500K output workload, Grok 4.3 is estimated at $2.5 vs $120 for GPT-5.5 Pro, saving $117.5 (97.9% lower).
High-volume input processing	Grok 4.3	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Grok 4.3	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	GPT-5.5 Pro	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Grok Build 0.1 can replace Grok 4.3 when lower sample workload cost matters most: $2.
gpt-oss-120b (free) can replace GPT-5.5 Pro when lower sample workload cost matters most: $0.
gpt-oss-20b (free) can replace GPT-5.5 Pro when lower sample workload cost matters most: $0.
gpt-oss-20b can replace GPT-5.5 Pro when lower sample workload cost matters most: $0.1.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.23 sample workload cost.
Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
Grok 4.20 offers 2M context with $2.5 sample workload cost.

Popular competitors

No popular competitor is currently available.

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

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Larger context alternatives

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Provider catalogs

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xAI catalog

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OpenAI catalog

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Grok 4.3

Grok 4.3 is a reasoning model from xAI. It accepts text and image inputs with text output, and is suited for agentic workflows, instruction-following tasks, and applications requiring high factual...

GPT-5.5 Pro

GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...