xAI

Grok 4.5

Grok 4.5 is a proprietary model from xAI, released Jul 8, 2026. It ranks #57 of 351 on the LMArena text leaderboard with a rating of 1448. It costs $2 per million input tokens and $6 per million output tokens, with a 500K-token context window.

LMArena text1448−2 in 30 days
Rank#57/351
95% interval1444–1452
Votes39.9K
Developer
xAI
Released
Jul 8, 2026
Context window
500K
Price in / out, per 1M tokens
$2 / $6
Weights
Proprietary
Inputs
Text, Images, Files
Reasoning
Yes
Tool use
Yes
Grok 4.5, LMArena text rating over time
14301440145014601470Jul 10Aug 5Aug 31Sep 26Oct 22
LatestGrok 4.5 1448

The rating LMArena published at each update since Jul 10, 2026. Ratings move as votes come in and new models join.

Benchmarks

BenchmarkScore barAccuracyRankCost / test
Terminal-Bench 4.0Coding8.59%42 / 55$5.52
SWE-benchCoding86.60%13 / 85$0.54
Vibe Code BenchCoding69.00%45 / 115$4.10
LiveCodeBenchCoding87.35%15 / 143$2 / $6
Tax Agent BenchFinance24.86%41 / 76$0.47
Legal Research BenchLaw37.98%41 / 85$1.09
MedCodeMedicine43.29%46 / 107$2 / $6
GPQA DiamondReasoning92.93%13 / 138$2 / $6
MMLU-ProReasoning89.22%14 / 138$2 / $6
MMMUReasoning61.79%83 / 93$2 / $6

Vals AI, as of Oct 24, 2026.

LMArena, by category

LeaderboardRatingRankVotes
TextLMArena144857 / 35139.9K
CodingLMArena147461 / 34611.1K
MathLMArena146058 / 3391.8K
Creative writingLMArena144240 / 3498.3K
Instruction followingLMArena144554 / 35114.5K
Hard promptsLMArena146253 / 35126.6K
Multi-turnLMArena145651 / 3496.6K
Long queriesLMArena146247 / 33019.3K
ExpertLMArena146565 / 3054.7K
Legal and governmentIndustries146347 / 3253.3K
Medicine and healthcareIndustries143998 / 3252.9K
Business and financeIndustries144154 / 3447.6K
ChineseLanguages149559 / 3283.1K
SpanishLanguages145160 / 2491.1K
GermanLanguages144856 / 261685
FrenchLanguages145772 / 2521.3K
JapaneseLanguages143142 / 236540
WebDevLMArena155344 / 12411.1K
VisionLMArena128731 / 14612.6K

LMArena, CC BY 4.0, as of Oct 22, 2026. Where a model is rated at several effort levels, its best is shown.

Compare Grok 4.5

xAI

The lab behind Grok, trained on one of the largest compute clusters and integrated with X. Founded 2023, based in San Francisco Bay Area. x.ai

Questions

Who makes Grok 4.5?

Grok 4.5 is made by xAI, founded 2023 and based in San Francisco Bay Area.

How much does Grok 4.5 cost?

$2 per million input tokens and $6 per million output tokens, at its provider’s list price.

What is Grok 4.5’s context window?

500K tokens (500,000).

How does Grok 4.5 rank?

#57 of 351 on LMArena’s text leaderboard, rated 1448 (95% interval 1444–1452) from 39,880 votes, as of Oct 22, 2026.

Is Grok 4.5 open source?

No. Grok 4.5 is proprietary and served through its provider’s API.

Sources

Every number on this page comes from these sources; models without a published number show none. Download the data. Cite as “Nexus Explorer, nexus.inc/models”.