// head_to_head
Kimi K3 vs Step 5 Preview
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.
Kimi K3 scores higher, Step 5 Preview costs less — it depends on your workload.
Kimi K3 is ahead by 1.4 points overall, and Step 5 Preview lists 2.8× cheaper per blended million tokens. Whether 1.4 points is worth that depends on how much a wrong answer costs you. The two cost measures disagree here, which is worth knowing: Step 5 Preview has the lower sticker price, but Kimi K3 earns each point of capability for less — $1.24 against $4.08 — because per-token rates do not predict how many tokens a model actually spends on a task.
moonshotai
Kimi K3
- Blended / 1M
- $4.00
- Context
- 1.0M
- Released
- Jul 16, 2026
- Overall score
- 63.4
stepfun
Step 5 Preview
- Blended / 1M
- $1.43
- Context
- 1.0M
- Released
- Oct 8, 2026
- Overall score
- 62.0
Specs and pricing
| Metric | Kimi K3 | Step 5 Preview |
|---|---|---|
| LiveBench overall Mean of the seven LiveBench category scores, 0–100. Higher is better. | 63.4win | 62.0 |
| Cost per point Measured benchmark spend divided by overall score — dollars per point of capability. | $1.24win | $4.08 |
| Blended price / 1M 3:1 input:output mix, the usual shape of production traffic. | $4.00 | $1.43win |
| Input price / 1M | $0.339win | $1.00 |
| Output price / 1M | $15.00 | $2.70win |
| Cached input / 1M Price of an input token served from the prompt cache, where the provider publishes one. | $0.237 | $0.100win |
| Context window | 1.0M | 1.0M |
| Max output tokens | 944Kwin | 64K |
Benchmarks by category
An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Kimi K3 on top, Step 5 Preview below, both out of 100.
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.
| Workload | Kimi K3 | Step 5 Preview |
|---|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $1,274/mo | $391.20/mo |
| RAG assistant 8K in / 600 out × 100K requests | $1,130/mo | $602.00/mo |
| Coding agent 40K in / 4K out × 20K requests | $1,414/mo | $512.00/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $1,459/mo | $1,158/mo |
| Bulk classification 500 in / 20 out × 5M requests | $2,297/mo | $2,320/mo |
Which should you pick?
You are running this at volume
Kimi K3
Lowest measured cost per point of capability at $1.24 per point — the gap compounds with every request.
Quality matters more than the bill
Kimi K3
Highest overall LiveBench score of the two at 63.4.
The workload is coding or agentic work
Step 5 Preview
Leads on coding — 85.6 against 59.3.
Kimi K3 vs Step 5 Preview FAQ
Which is better, Kimi K3 or Step 5 Preview?
Kimi K3 scores higher, Step 5 Preview costs less — it depends on your workload. Kimi K3 is ahead by 1.4 points overall, and Step 5 Preview lists 2.8× cheaper per blended million tokens. Whether 1.4 points is worth that depends on how much a wrong answer costs you. The two cost measures disagree here, which is worth knowing: Step 5 Preview has the lower sticker price, but Kimi K3 earns each point of capability for less — $1.24 against $4.08 — because per-token rates do not predict how many tokens a model actually spends on a task.
Is Kimi K3 cheaper than Step 5 Preview?
Step 5 Preview is cheaper. On a 3:1 input:output blend, Kimi K3 lists at $4.00 per million tokens and Step 5 Preview at $1.43 — Step 5 Preview is 2.8× cheaper. Input and output are priced separately — Kimi K3 charges $0.339 in and $15.00 out, Step 5 Preview charges $1.00 and $2.70 — so the model that looks cheaper flips depending on how output-heavy your workload is.
Kimi K3 vs Step 5 Preview: which scores higher on benchmarks?
Kimi K3 scores 63.4 and Step 5 Preview scores 62.0 overall on LiveBench, the mean of its seven categories. That is a 1.4-point lead for Kimi K3. 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 K3 or Step 5 Preview?
Kimi K3. 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 K3 works out at $1.24 per point and Step 5 Preview at $4.08.
Does Kimi K3 or Step 5 Preview have a bigger context window?
They are effectively the same — 1.0M for Kimi K3 and 1.0M for Step 5 Preview.
Do Kimi K3 and Step 5 Preview support prompt caching?
Both publish a cached-input rate: $0.237 per million for Kimi K3 and $0.100 for Step 5 Preview, against full input rates of $0.339 and $1.00. 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.
- Scores — LiveBench release 2026-09-02, 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.