AI model comparison

Grok Build 0.1 vs Grok 4.20

Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.

Grok Build 0.1 is SpaceXAI’s fast coding model trained specifically for agentic software engineering workflows.

Input / 1M
$1
Output / 1M
$2
Context
256K

Grok 4.20 is a reasoning model from SpaceXAI with industry-leading speed and agentic tool calling capabilities.

Input / 1M
$1.25
Output / 1M
$2.50
Context
2M

At a glance

Quick verdict

How the two models stack up on the things people ask about most.

Lower price

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Grok Build 0.1

1.3x cheaper for a typical chat

Higher intelligence score

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Grok Build 0.1

27.2 vs 25.7 on Artificial Analysis

Larger context window

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Grok 4.20

2M vs 256K tokens

Newer release

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Grok Build 0.1

Released May 20, 2026

Benchmarks

Benchmark scores

Independent scores from Artificial Analysis. Higher is better.

Intelligence index

x-ai logoGrok Build 0.127.2
x-ai logoGrok 4.2025.7

Coding index

x-ai logoGrok Build 0.151.5
x-ai logoGrok 4.20Not available

Agentic index

x-ai logoGrok Build 0.1Not available
x-ai logoGrok 4.20Not available

Pricing

Grok Build 0.1 vs Grok 4.20 API pricing

Per-token API rates. Cheaper option highlighted.

Metricx-ai logoGrok Build 0.1x-ai logoGrok 4.20
Input tokensPer 1M tokens$1$1.25
Output tokensPer 1M tokens$2$2.50
Cached input (read)Per 1M tokens$0.20$0.20
Cache writePer 1M tokensNot availableNot available
Long-context pricingPer 1M tokens, for very long prompts$2 in / $4 out above 200K$2.50 in / $5 out above 200K
Web searchPer request$0.005$0.005

What it costs in practice

Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.

Chat message

2K in, 500 out

x-ai logoGrok Build 0.1$3
x-ai logoGrok 4.20$3.75

Coding task

30K in, 4K out

x-ai logoGrok Build 0.1$38$14 cached
x-ai logoGrok 4.20$47.50$16 cached

Long document summary

150K in, 2K out

x-ai logoGrok Build 0.1$154$34 cached
x-ai logoGrok 4.20$192.50$35 cached

Specs

Context window and capabilities

How much each model can read, how much it can write, and what it accepts as input.

Metricx-ai logoGrok Build 0.1x-ai logoGrok 4.20
Context window256K tokens2M tokens
Max output230K tokens1.80M tokens
Input typesFile, Image, TextFile, Image, Text
Output typesTextText
Reasoning effort levelsNot availableNot available
Default reasoning effortNot availableNot available
Release dateMay 20, 2026March 31, 2026

Features

Supported features

API features available for each model.

Metricx-ai logoGrok Build 0.1x-ai logoGrok 4.20
Tool callingSupportedSupported
Structured outputsSupportedSupported
JSON modeSupportedSupported
ReasoningSupportedSupported
TemperatureSupportedSupported
Stop sequencesNot supportedNot supported
Deterministic seedSupportedSupported
Verbosity controlNot supportedNot supported

Our take

Grok Build 0.1 is 1.3x cheaper for a typical chat. Grok Build 0.1 scores higher on the Artificial Analysis Intelligence Index (27.2 vs 25.7). Grok 4.20 has the larger context window (2M vs 256K tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.

FAQ

Frequently asked questions

Is Grok Build 0.1 or Grok 4.20 cheaper?

Grok Build 0.1 is cheaper for a typical chat (2K input tokens and 500 output tokens). Grok Build 0.1 costs $1 per 1M input tokens and $2 per 1M output tokens, while Grok 4.20 costs $1.25 per 1M input tokens and $2.50 per 1M output tokens.

Which has a bigger context window, Grok Build 0.1 or Grok 4.20?

Grok 4.20 supports up to 2M tokens of context, compared with 256K for Grok Build 0.1.

Is Grok Build 0.1 smarter than Grok 4.20?

On the Artificial Analysis Intelligence Index, Grok Build 0.1 scores 27.2 and Grok 4.20 scores 25.7, putting Grok Build 0.1 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.

Can I use Grok Build 0.1 and Grok 4.20 at the same time?

Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Grok Build 0.1 and Grok 4.20 answer side by side and keep the better response.

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Why choose? Ask both.

Send one prompt to Grok Build 0.1 and Grok 4.20 at the same time. Compare the answers side by side and keep the best one.