API cost decision in 10 seconds

NewGrok Build 0.1 vs Grok 4.20

Pick Grok Build 0.1 for lower cost; pick Grok 4.20 only if the larger context window matters more.

Page updated: 2026-05-26T10:03:26Z Data confirmed: 2026-05-26T12:43:06Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Grok Build 0.1 for lower cost; pick Grok 4.20 only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Grok Build 0.1 is estimated at $2 vs $2.5 for Grok 4.20, saving $0.5 (20% lower).

Cost-first pickGrok Build 0.1

Context-first pickGrok 4.20

Sample savings$0.520%

10x traffic gap$5

Grok 4.20 has more context, but Grok Build 0.1 saves $0.5 on the standard workload. At 10x that traffic, the same price gap is about $5. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Grok Build 0.1 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Grok Build 0.1	Grok 4.20
Input-heavy / RAG	5M input + 500K output	Grok Build 0.1	$6	$7.5
Balanced workload	1M input + 1M output	Grok Build 0.1	$3	$3.75
Output-heavy chatbot	1M input + 5M output	Grok Build 0.1	$11	$13.75

Cheaper input Grok Build 0.1 $1 vs $1.25 / 1M

Grok Build 0.1 is $0.25 cheaper per 1M input tokens (20% lower; 1.25x difference).

Cheaper output Grok Build 0.1 $2 vs $2.5 / 1M

Grok Build 0.1 is $0.5 cheaper per 1M output tokens (20% lower; 1.25x difference).

Larger context Grok 4.20 256K vs 2M

Grok 4.20 has 1.74M more context (7.81x larger).

Sample workload Grok Build 0.1 $2 vs $2.5

Grok Build 0.1 is $0.5 cheaper on the standard workload (20% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Grok Build 0.1 Calculating… Estimated API cost

Grok 4.20 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 Build 0.1 has the lower input price; Grok Build 0.1 has the lower output price; Grok 4.20 offers the larger context window. For the 1M input plus 500K output sample, Grok Build 0.1 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $2 for Grok Build 0.1 and $2.5 for Grok 4.20.

Best Fit

Choose Grok Build 0.1 when you care most about lower input-token price, and lower output-token price.

Choose Grok 4.20 when you care most about larger context window.

Decision Notes

On the standard 1M input plus 500K output workload, Grok Build 0.1 is estimated at $2 vs $2.5 for Grok 4.20, saving $0.5 (20% lower).
Grok Build 0.1 is $0.5 cheaper on the standard workload (20% lower).
Grok Build 0.1 is $0.25 cheaper per 1M input tokens (20% lower; 1.25x difference).
Grok Build 0.1 is $0.5 cheaper per 1M output tokens (20% lower; 1.25x difference).
Grok 4.20 has 1.74M more context (7.81x larger).

Head-to-Head Specs

Feature	NewGrok Build 0.1 (xAI)	Grok 4.20 (xAI)
Input Price prompt tokens per 1M	$1	$1.25
Completion Price per 1M tokens	$2	$2.5
Sample Workload Cost 1M input + 500K output	$2	$2.5
Context Window	256K	2M
Release Date	2026-05-20	2026-03-31

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Grok Build 0.1	On the standard 1M input plus 500K output workload, Grok Build 0.1 is estimated at $2 vs $2.5 for Grok 4.20, saving $0.5 (20% lower).
High-volume input processing	Grok Build 0.1	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Grok Build 0.1	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Grok 4.20	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

No lower-cost same-provider swap is currently tracked for this pair.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.23 sample workload cost.

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Provider catalogs

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xAI catalog

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Grok Build 0.1

Grok Build 0.1 is xAI’s fast coding model trained specifically for agentic software engineering workflows. It supports text and image inputs with text output, and is optimized for interactive coding...

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