Models

Grok 4.20 Beta 0309 (reasoning) vs Grok 4.5

Output tokens cost $6.00 per million on Grok 4.20 Beta 0309 (reasoning) and $6.00 per million on Grok 4.5. Input tokens cost $2.00 per million on Grok 4.20 Beta 0309 (reasoning) and $2.00 per million on Grok 4.5. Cached input tokens are billed at $0.20 per million on Grok 4.20 Beta 0309 (reasoning) and $0.50 per million on Grok 4.5. Context lengths are 2,000,000 tokens on Grok 4.20 Beta 0309 (reasoning) and 500,000 tokens on Grok 4.5. Time to first token (TTFT) measured on AIHubMix is 1.7s on Grok 4.20 Beta 0309 (reasoning) and 1.9s on Grok 4.5. Measured output throughput is 74.3 tok/s on Grok 4.20 Beta 0309 (reasoning) and 26.7 tok/s on Grok 4.5. On the LMArena coding leaderboard Grok 4.20 Beta 0309 (reasoning) scores 1511 and Grok 4.5 scores 1523.

GrokGrok 4.20 Beta 0309 (reasoning)GrokGrok 4.5
Grok logo
Grok 4.20 Beta 0309 (reasoning)
Grok · text, image → text

Grok 4.20 Beta is our latest flagship model, offering industry-leading speed and agent tool-invocation capabilities. It combines the lowest hallucination rate on the market with strict prompt adherence, enabling it to consistently deliver precise and factual responses.

Input$2.00 /M
Output$6.00 /M
Grok logo
Grok 4.5
Grok · text, image → text

Grok 4.5 was trained on datasets spanning knowledge in coding, science, engineering, and math. With both intelligent and efficient reasoning, Grok 4.5 excels at real engineering tasks and exceeds comparable leading models at these tasks.

Input$2.00 /M
Output$6.00 /M

Pricing & Specifications

Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.

Grok 4.20 Beta 0309 (reasoning)
Grok 4.5
Input /M
$2.00
$2.00
Output /M
$6.00
$6.00
Cache read /M
$0.20
$0.50
Context length
2,000,000
500,000
Max output
2,000,000
500,000
Time to First Token
1.7 s
1.9 s
Throughput
74.3 tok/s
26.7 tok/s
Modalities
textimage
textimage
Supported Parameters
thinkingtoolsfunction callingstructured outputslong context
thinkingtoolsfunction callingstructured outputslong context
API Formats
Released
-
July 2026

Promotional prices show the discounted rate; see each model page for promotion windows.

Activity Past 30 Days

Daily traffic served through AIHubMix — how demand for each model is trending.

grok-4.20-beta-0309-reasoninggrok-4.5

Tokens / day

-

Requests / day

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Performance Past 3 Days

Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.

grok-4.20-beta-0309-reasoninggrok-4.5

Throughput (tok/s)

-

TTFT (s)

-

Uptime (%)

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LMArena Benchmarks

LMArena ratings by capability (Bradley-Terry, commonly called Elo). Higher is better.

Text
grok-4.20-beta-0309-reasoninggrok-4.5
1420146015001540
Overall
14701472
Coding
15111523
Math
14671478
Hard prompts
14881495
Instruction following
14461466
Multi-turn
14771480
Creative writing
14471449
Longer query
14661485
Chinese
15031511
English
14751478
Vision
grok-4.20-beta-0309-reasoninggrok-4.5
1240128013201360
Overall
12561282
OCR
12661295
Diagram
12741321
Homework
12611328
WebDev Arena
grok-4.20-beta-0309-reasoninggrok-4.5
1320140014801560
Overall
13741556
React
13671559
HTML
13681577
Gaming
13541586
Simulations
13481598
Data analytics
13591522

Source: LMArena (arena.ai) leaderboard, imported by AIHubMix. Models without published ratings are omitted per chart.

Cost calculator

Estimate your monthly bill for the same workload on each model.

Grok 4.20 Beta 0309 (reasoning)
$210 /mo
Grok 4.5
$210 /mo

Monthly = daily × 30. Discounted rates applied where a promotion is active.

FAQ

Which is cheaper: Grok 4.20 Beta 0309 (reasoning), Grok 4.5?

Grok 4.20 Beta 0309 (reasoning): $6.00/M output tokens; Grok 4.5: $6.00/M. Use the cost calculator above to estimate your own workload.

How do their coding arena scores compare?

Grok 4.5: 1523; Grok 4.20 Beta 0309 (reasoning): 1511 (LMArena coding leaderboard).

Which responds faster?

Grok 4.20 Beta 0309 (reasoning): 1.7s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.

How large is each context window?

Grok 4.20 Beta 0309 (reasoning) accepts 2,000,000 and Grok 4.5 accepts 500,000 input tokens. Maximum output per request is 2,000,000 tokens on Grok 4.20 Beta 0309 (reasoning) and 500,000 tokens on Grok 4.5.

Which one generates tokens faster?

Grok 4.20 Beta 0309 (reasoning) at 74.3 tok/s and Grok 4.5 at 26.7 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.

What inputs and capabilities does each model support?

Grok 4.20 Beta 0309 (reasoning) accepts text and image input and supports thinking, tool calling, function calling, structured outputs and long context; Grok 4.5 accepts text and image input and supports thinking, tool calling, function calling, structured outputs and long context.

Can I call Grok 4.20 Beta 0309 (reasoning) and Grok 4.5 with the same API key?

Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.

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