ModelsCompareBest forBenchmarksStatusPricingAPI
Compare / head-to-head

Grok 4 Fast ReasoningvsLongCat Flash Chat

Grok 4 Fast Reasoning leads 2 of 2 shared benchmarks. Grok 4 Fast Reasoning has the larger context window (2M tokens).

Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.

Shared benchmarks
2 – 0
Grok 4 Fast Reasoning leads
Cheaper per token
list price, input + output
Larger context
Grok 4 Fast Reasoning
2M tokens
Provider uptime (30d)
— · —
xAI · Meituan LongCat
Grok 4 Fast Reasoning
xAI · released 2025-09-19
text
Context
2M
Max out
Input /1M
$0.2
Output /1M
$0.5
Cached /1M
$0.05
Scores
12 · 4 core
LongCat Flash Chat
Meituan LongCat · released 2025-09-01
text
Context
128K
Max out
Input /1M
Output /1M
Cached /1M
Scores
31 · 9 core
Quality

Benchmark matrix

BenchmarkGrok 4 Fast ReasoningLongCat Flash ChatΔEdge
Reported by both · 2
GPQA Diamond85.7% 73.23% +12.5 ptGrok 4 Fast Reasoning
AIME 202592% 61.25% +30.8 ptGrok 4 Fast Reasoning
Only Grok 4 Fast Reasoning reports · 10
Humanity's Last Exam (no tools)20% not reported
BrowseComp44.9% not reported
BrowseComp (zh)51.2% not reported
HMMT 2025 (no tools)93.3% not reported
LiveCodeBench (Jan-May)80% not reported
Reka Research Eval66% not reported
Search Arena Elo1163 not reported
SimpleQA95% not reported
X Bench Deepsearch (zh)74% not reported
X Browse58% not reported
Only LongCat Flash Chat reports · 29
SWE-bench Verifiednot reported60.4%
MMLUnot reported89.71%
MMLU-Pronot reported82.68%
LMArena Elonot reported1422.9
AceBenchnot reported76.1%
AIME 2024not reported70.42%
ArenaHard-V2not reported86.5%
BeyondAIMEnot reported43%
C-Evalnot reported90.44%
CMMLUnot reported84.34%
COLLIEnot reported57.1%
DROPnot reported79.06%
GraphWalks-128knot reported51.05%
HumanEval+not reported88.41%
IFEvalnot reported89.65%
LiveCodeBenchnot reported48.02%
MATH500not reported96.4%
MBPP+not reported79.63%
Meeseeks-zhnot reported43.03%
Safety: Criminalnot reported91.24%
Safety: Harmfulnot reported83.98%
Safety: Misinformationnot reported81.72%
Safety: Privacynot reported93.98%
Tau2-Bench (airline)not reported58%
Tau2-Bench (retail)not reported71.27%
Tau2-Bench (telecom)not reported73.68%
TerminalBenchnot reported39.51%
VitaBenchnot reported24.3%
ZebraLogicnot reported89.3%
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is Grok 4 Fast Reasoning minus LongCat Flash Chat in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing

Side by side

SpecGrok 4 Fast ReasoningLongCat Flash ChatEdge
Context window2M tokens128K tokensGrok 4 Fast Reasoning
Max output
Input price / 1M$0.2
Output price / 1M$0.5
Cached input / 1M$0.05
Input + output / 1M
Lower is cheaper. List prices; batch, tool and regional fees excluded.
$0.7
ModalitiestexttextTie
Released2025-09-192025-09-01
Cited benchmark scores1231
Reliability

Provider status

All providers
More matchups

Grok 4 Fast Reasoning vs …

More matchups

LongCat Flash Chat vs …

Built by Respan
Which one wins on your data?

Public benchmarks are a starting point. Run Grok 4 Fast Reasoning and LongCat Flash Chat on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.