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Kimi K2.6 vs SpaceXAI: Grok 4.5

Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.

OpenRouter + LiveBenchAll comparisonsFull leaderboard

SpaceXAI: Grok 4.5 scores higher, Kimi K2.6 costs less — it depends on your workload.

SpaceXAI: Grok 4.5 is ahead by 5.2 points overall, and Kimi K2.6 lists 3.0× cheaper per blended million tokens. Whether 5.2 points is worth that depends on how much a wrong answer costs you. The two cost measures disagree here, which is worth knowing: Kimi K2.6 has the lower sticker price, but SpaceXAI: Grok 4.5 earns each point of capability for less — $0.0720 against $0.0918 — because per-token rates do not predict how many tokens a model actually spends on a task.

moonshotai

Kimi K2.6

Blended / 1M
$1.01
Context
262K
Released
Apr 20, 2026
Overall score
70.5
reasoningtool callingimage inputprompt caching

x-ai

SpaceXAI: Grok 4.5

Blended / 1M
$3.00
Context
500K
Released
Jul 8, 2026
Overall score
75.8
reasoningtool callingimage inputfile inputprompt caching

Specs and pricing

MetricKimi K2.6SpaceXAI: Grok 4.5
LiveBench overall

Mean of the seven LiveBench category scores, 0–100. Higher is better.

70.575.8win
Cost per point

Measured benchmark spend divided by overall score — dollars per point of capability.

$0.0918$0.0720win
Blended price / 1M

3:1 input:output mix, the usual shape of production traffic.

$1.01win$3.00
Input price / 1M$0.560win$2.00
Output price / 1M$2.36win$6.00
Cached input / 1M

Price of an input token served from the prompt cache, where the provider publishes one.

$0.094win$0.300
Context window262K500Kwin
Max output tokens262K

Benchmarks by category

An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Kimi K2.6 on top, SpaceXAI: Grok 4.5 below, both out of 100.

Agentic coding
46.9
56.5
Coding
78.6
68.6
Reasoning
79.4
87.2
Mathematics
84.3
90.8
Data analysis
65.1
73.0
Language
75.1
82.8
Instruction following
64.4
71.5

What each one costs to run

Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.

WorkloadKimi K2.6SpaceXAI: Grok 4.5
Support chatbot

1.2K in / 400 out × 200K requests

$289.76/mo$837.60/mo
RAG assistant

8K in / 600 out × 100K requests

$403.56/mo$1280.00/mo
Coding agent

40K in / 4K out × 20K requests

$376.18/mo$1128.00/mo
Document extraction

20K in / 1.5K out × 50K requests

$714.19/mo$2365.00/mo
Bulk classification

500 in / 20 out × 5M requests

$1404.20/mo$4750.00/mo
Run these two through the cost calculator

Which should you pick?

You are running this at volume

SpaceXAI: Grok 4.5

Lowest measured cost per point of capability at $0.0720 per point — the gap compounds with every request.

Quality matters more than the bill

SpaceXAI: Grok 4.5

Highest overall LiveBench score of the two at 75.8.

The workload is coding or agentic work

SpaceXAI: Grok 4.5

Leads on agentic coding — 56.5 against 46.9.

You need to fit large documents in one call

SpaceXAI: Grok 4.5

Wider context window — 500K against 262K.

You are cost-constrained

Kimi K2.6

Cheaper on blended list price at $1.01 per million tokens.

Kimi K2.6 vs SpaceXAI: Grok 4.5 FAQ

Which is better, Kimi K2.6 or SpaceXAI: Grok 4.5?

SpaceXAI: Grok 4.5 scores higher, Kimi K2.6 costs less — it depends on your workload. SpaceXAI: Grok 4.5 is ahead by 5.2 points overall, and Kimi K2.6 lists 3.0× cheaper per blended million tokens. Whether 5.2 points is worth that depends on how much a wrong answer costs you. The two cost measures disagree here, which is worth knowing: Kimi K2.6 has the lower sticker price, but SpaceXAI: Grok 4.5 earns each point of capability for less — $0.0720 against $0.0918 — because per-token rates do not predict how many tokens a model actually spends on a task.

Is Kimi K2.6 cheaper than SpaceXAI: Grok 4.5?

Kimi K2.6 is cheaper. On a 3:1 input:output blend, Kimi K2.6 lists at $1.01 per million tokens and SpaceXAI: Grok 4.5 at $3.00 — Kimi K2.6 is 3.0× cheaper. Input and output are priced separately — Kimi K2.6 charges $0.560 in and $2.36 out, SpaceXAI: Grok 4.5 charges $2.00 and $6.00 — so the model that looks cheaper flips depending on how output-heavy your workload is.

Kimi K2.6 vs SpaceXAI: Grok 4.5: which scores higher on benchmarks?

Kimi K2.6 scores 70.5 and SpaceXAI: Grok 4.5 scores 75.8 overall on LiveBench, the mean of its seven categories. That is a 5.2-point lead for SpaceXAI: Grok 4.5. Category scores differ from the overall figure — a model can lead on reasoning and trail on coding, which the per-category table above breaks out.

Which gives better value for money, Kimi K2.6 or SpaceXAI: Grok 4.5?

SpaceXAI: Grok 4.5. Cost per point divides the measured dollars LiveBench spent running the benchmark by the score it earned, so it captures something token pricing misses: a reasoning model can emit many times more tokens than its per-token rate suggests. Kimi K2.6 works out at $0.0918 per point and SpaceXAI: Grok 4.5 at $0.0720.

Does Kimi K2.6 or SpaceXAI: Grok 4.5 have a bigger context window?

SpaceXAI: Grok 4.5 has the larger context window: 262K for Kimi K2.6 against 500K for SpaceXAI: Grok 4.5. Note that a window you can fill is not a window you should fill — retrieval quality usually degrades well before the limit, and you pay for every token you put in it.

Do Kimi K2.6 and SpaceXAI: Grok 4.5 support prompt caching?

Both publish a cached-input rate: $0.094 per million for Kimi K2.6 and $0.300 for SpaceXAI: Grok 4.5, against full input rates of $0.560 and $2.00. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.

Related comparisons

How these numbers are produced

  • Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
  • ScoresLiveBench release 2026-06-25, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
  • Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
  • “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.

Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.