Kimi K3 benchmark · coding agent evaluation

Kimi K3 benchmark results, costs, and an evaluation plan

A maintained reading guide for Kimi K3 coding-agent benchmarks: separate the model from the harness, pass rate from cost, and vendor claims from independent measurements. This is an independent guide, not a Moonshot/Kimi official page.

Release update: Kimi's official overview lists K3's July 16, 2026 release and July 27 full-weight availability. The open-weight repository now documents a 2.8T MoE model, 104B activated parameters, MXFP4 weights, MXFP8 activations, and 1,048,576-token context. Treat local serving as a cluster/inference-engine project, not a laptop install promise.
Research status: Semrush US Volume/KD/CPC/Intent and variants were not obtained in this round. Google Trends US past-7-day comparison supplied for this brief shows Kimi K3 around 31 relative mean versus opencode around 8; interest continued after July 16, but this page does not call it a confirmed Breakout.

Last reviewed: 2026-07-28. The search snapshot is an estimate for trend direction, not raw search volume. Similarweb project insight also suggested nxcode.io added Kimi K3 benchmark content and organic terms; that observation may be delayed or estimated.

Evidence table

Compare measurements without flattening them

8 of 8 records

K3, GPT, Claude, and Fable appear here as named measurement points. A score is only meaningful with its harness, benchmark, and evidence type attached.

ModelHarness / benchmarkMetric / valuePass rateCostLatency / effortEvidence and caveat
Kimi K3Coding agentFireworks agent harnessSWE-style repository tasksTask solve rate92.4%92.4% task solveProvider study says lower across this mix; up to 50× claim for routingNot normalized; about 55 turns / 1.3M tokens on SWEFireworks study Provider study · 2026-07-28Same-harness comparison, not a universal model ranking.
Kimi K3Agentic knowledgeArtificial Analysis evaluation harnessAA-BriefcaseElo1543Not a pass rateArticle says more expensive than Opus 4.8 to runNearly one hour per task on averageArtificial Analysis Independent · 2026-07-28Private realistic tasks and Elo measure knowledge work, not repo repair.
Kimi K3Model profileMoonshot API / official model docsModel capability profileContext / tool capability1M context; tools documentedNot reportedSee official per-token pricingMeasure on your provider and regionKimi K3 API docs Vendor-reported · 2026-07-28Official capability claims describe the model, not an independent evaluation.
Claude Fable 5Coding agentFireworks agent harnessSWE-style repository tasksTask solve rate92.6%92.6% task solveReference point for the provider's routing analysisAbout 21 turns / 130K tokens on SWEFireworks study Provider study · 2026-07-28Task mix and harness shape the result; do not transfer it to chat quality.
Claude Fable 5Agentic knowledgeArtificial Analysis evaluation harnessAA-BriefcaseElo1574Not a pass rateComparator in the same articleNot reported in the page snapshot used hereArtificial Analysis Independent · 2026-07-28Second place here does not imply second place for coding agents.
GPT-5.6 SolModel profileOpenLM comparison boardBoard snapshotListingListed; score not copiedNot comparable hereProvider and route dependentProvider and route dependentOpenLM board Board snapshot · 2026-07-28A board listing is a discovery signal, not a same-harness result.
Claude Opus 4.8Model profileOpenLM comparison boardBoard snapshotListingListed; score not copiedNot comparable hereProvider and route dependentProvider and route dependentOpenLM board Board snapshot · 2026-07-28Keep this row separate from K3's Fireworks and AA measurements.
Kimi K2.7 / frontier comparatorsEvaluation methodPydantic AI or vendor agent SDKsGrounded security benchmark methodologyPrecision / recall / F1Method reference; not a K3 scoreNot a K3 scoreCost per scan / true positiveRepeat runs to measure stabilitySemgrep methodology Method guide · 2026-07-28Evaluation design reference, not evidence about K3 itself.

How to read the table

Three distinctions prevent benchmark bait

Model ≠ harness

A K3 API call, a Fireworks agent loop, and a local MCP agent can produce different results even with the same weights.

Benchmark ≠ product

SWE-style repair, AA-Briefcase knowledge work, frontend Arena, and a security benchmark answer different questions.

Pass rate ≠ cost

Record tokens, cache hits, turns, retries, and wall-clock time. A lower rate can still win a narrow workload; a headline score does not price a task.

Kimi K3 pricing and limits

Use API rates as a cost input, not a quality claim

Moonshot's current Kimi API documentation describes K3 as a 1M-token-context model, always thinking, with configurable reasoning_effort and automatic context caching. The pricing page is the source of truth for cache-hit, cache-miss, and output rates; provider routes and subscriptions should not be mixed into one number.

$0.30 cache-hit input · $3 cache-miss input · $15 output per 1M tokens Check taxes, account tier, route, and the official rate card before budgeting.

Kimi K3 API, Kimi Code, or local weights?

These are three different operating surfaces

Kimi API

Hosted `kimi-k3` access with OpenAI/Anthropic-compatible requests, per-token billing, 1M context, and provider-side quota. Best for a fast baseline and controlled cost traces.

API quickstart
Kimi Code

A coding-agent harness that can select K3 and own the terminal workflow. Its task success, tool permissions, retries, and context policy must be benchmarked separately from the model.

Official Kimi Agent overview
Local / self-hosted

Full weights are available in the official repository. The README recommends vLLM, SGLang, or TokenSpeed; MXFP4 and a 1M context do not imply a single-GPU or consumer-hardware minimum. Size GPU memory, interconnect, KV cache, throughput, and concurrency together.

Official Kimi K3 repository

Kimi K3 cost estimator

Model cache hits, retries, and long context before you budget

Estimate only

Enter workload assumptions to estimate Kimi K3 API spend. The calculator uses the reviewed K3 rate card: $0.30/M cache-hit input, $3/M cache-miss input, and $15/M output. Retries are counted as additional calls.

Illustrative baseline for difference onlyThese editable rates are not a live GPT/Claude quote.
Estimated monthly$60.541,000 billed calls
Per original request$0.06including retry assumption
Difference vs baseline$61.96baseline monthly: $122.50

Not a quote: actual invoices can vary with provider route, account tier, rounding, cached prefix shape, tool-call output, taxes, retries, and long-context behavior. Verify the official rate card before making a purchasing decision. The long-context multiplier is a planning assumption, not a Kimi promise.

Prompts and workload scenarios

Evaluate K3 where your agent actually works

API and coding agent

Measure tool-call validity, retries, test-backed task solve, tokens, and wall-clock latency with the same harness.

Prompt starter: Inspect this repository, propose a patch, run the tests, and explain every changed file.
Kimi K3 frontend code arena

Use fixed screenshots, accessibility checks, responsive breakpoints, and a human rubric; visual polish is not a repository pass rate.

Prompt starter: Build the supplied UI brief without changing the acceptance criteria.
Repository refactoring

Track typecheck, test coverage, diff size, regression rate, and rollback quality across a pinned fixture.

Prompt starter: Refactor only the named module and preserve its public API.
Terminal and MCP

Evaluate permission boundaries, network egress, secrets handling, approval pauses, tool schemas, and audit logs alongside task success.

Prompt starter: Use allowlisted tools only; stop and request approval before writes or network calls.

Kimi K3 + MCP

Evaluate the boundary around the model

Kimi's API supports tool calls and dynamic tool loading. MCP is an agent integration and permission layer, not a benchmark score. If the harness can read files, execute commands, browse, or call a proxy, record those capabilities and approval rules beside the result.

model: kimi-k3
reasoning_effort: high
tools:
  - read_repo
  - run_tests
  - mcp_proxy (allowlist only)
  • Pin tool schemas and tool-result fixtures.
  • Deny secrets, unrestricted egress, and destructive writes by default.
  • Log tool calls, retries, tokens, latency, and human overrides.

Coding-agent evaluation · MCP safety checklist

Copy a repeatable K3 test template

0 / 8 ready
Evaluation template
[ ] Pin the exact model ID, reasoning effort, provider, and date.
[ ] Keep the agent harness, tool definitions, system prompt, and retry policy identical.
[ ] Use a held-out task set with reproducible repositories, dependencies, and fixtures.
[ ] Record pass rate, partial credit, test evidence, and human adjudication separately.
[ ] Log input/output tokens, cache hits, turns, wall-clock latency, and failures.
[ ] Run repeated trials to expose nondeterminism, timeout, and flaky tool-call behavior.
[ ] Check security boundaries: secrets, network egress, MCP tools, and write permissions.
[ ] Publish raw prompts, harness version, exclusions, and uncertainty with the conclusion.

Use the output as a test plan. It is not a certification that K3, GPT, Claude, or any agent is safe or best.

Sources and update method

What is current, what is estimated, and what to re-check

Data cutoff

Page review: 2026-07-28. Search trend values are the supplied US 7-day relative snapshot. Model, API, benchmark, and provider pages can change.

Independent versus vendor

Artificial Analysis and Semgrep use their own evaluation designs. Fireworks' K3/Fable result is a provider study. Moonshot's capability and pricing claims are vendor documentation.

Security and reproducibility

Do not run an agent benchmark against production secrets or unrestricted network access. Pin prompts, harness versions, dependencies, and task fixtures.

FAQ

Questions to answer before calling a benchmark result

What is the Kimi K3 benchmark?

Kimi K3 benchmark is not one test. This page compares coding-agent, agentic knowledge, model-board, and evaluation-method evidence while keeping each harness and score attached to its source.

Is Kimi K3 the best coding model?

No absolute conclusion is justified from the available snapshots. K3 is competitive on some coding and agentic measurements, but task mix, harness, cost, latency, and provider behavior can change the result.

How does Kimi K3 compare with Fable, GPT, or Claude?

Fireworks reports a near-tie between K3 and Claude Fable 5 on its same-harness task mix, while Artificial Analysis reports an AA-Briefcase Elo comparison. GPT and Claude board rows are kept separate when the same benchmark and harness are not available.

How much does Kimi K3 cost?

The official Kimi API pricing page should be checked before budgeting. The reviewed snapshot shows separate cache-hit input, cache-miss input, and output rates; Kimi subscriptions, Moonshot API, Fireworks, OpenRouter, and self-hosting are different cost surfaces.

Can I use Kimi K3 with MCP?

Kimi's API documents tool calls and dynamic tool loading. MCP support depends on the agent or proxy around the model, so evaluate permissions, tool schemas, network egress, logs, and approvals as part of the harness.

Are the Kimi K3 search figures official?

No. Semrush figures were not obtained. The page records a supplied US 7-day Google Trends relative snapshot of about 31 for Kimi K3 versus about 8 for opencode, plus sustained interest after July 16, without calling it a confirmed Breakout.