Model comparison · accepted catalogue facts 2026-10-21
Claude Opus 5 vs Kimi K3
Neither model has both an equal-or-higher measured score and an equal-or-lower estimated price in this pair. Retaining your current model is a valid outcome.
Editorial comparison: Cross-provider head-to-head: Claude Opus 5 (Anthropic) vs Kimi K3 (Moonshot AI) on intelligence, speed, and pricing Inclusion does not recommend either model.
Balanced effective USD / 1M tokens · lower is better
$3.05/M
Price under confirmation since Oct 13, 2026
In-Depth Analysis
Claude Opus 5 vs Kimi K3: Measured Technical Breakdown
Comprehensive comparison across measured human-preference evaluation, effective production token costs, architectural limits, and migration trade-offs.
Measured Capability (LMArena)
Claude Opus 5 leads by 26.9 Elo
Claude Opus 5: 1502.5 ±3.68 · Kimi K3: 1475.6 ±4.6 Statistically significant preference separation
Cost Comparison Across Canonical Production Workloads
Rates represent effective cost per 1M tokens under standard token blends. Cached prompt reads are factored according to workload context reuse.
Workload & Ratio
Claude Opus 5
Kimi K3
Cost Difference
Advantage
Balanced3 tokens in per 1 out
$10.00/1M tokens
$3.05/1M tokens
$6.95(70% diff)
Kimi K3 costs less
SummariseHuge input, tiny output
$4.72/1M tokens
$1.14/1M tokens
$3.58(76% diff)
Kimi K3 costs less
ChatLong cached system prompt
$11.65/1M tokens
$4.38/1M tokens
$7.27(62% diff)
Kimi K3 costs less
Code genOutput dominates
$16.64/1M tokens
$6.28/1M tokens
$10.36(62% diff)
Kimi K3 costs less
AgenticContext replayed each turn
$5.32/1M tokens
$2.01/1M tokens
$3.31(62% diff)
Kimi K3 costs less
Architectural & Operational Specifications
Specification
Claude Opus 5
Kimi K3
Operational Note
Context window
1,000,000 tokens
1,048,576 tokens
—
Max output generation
128,000 tokens
943,718 tokens
Kimi K3 allows longer single-turn completions
Base input price
$5.00 / 1M tokens
$0.730 / 1M tokens
Kimi K3 input rate is cheaper
Base output price
$25.00 / 1M tokens
$10.00 / 1M tokens
Kimi K3 output rate is cheaper
Cached input price
$0.500 / 1M tokens
$0.550 / 1M tokens
Claude Opus 5 offers lower cached prompt cost
Reasoning & thinking tokens
Supported; standard rates
Supported; standard rates
—
Input modalities
text, image, file
text, image, video
—
Tool calling / function use
Supported
Supported
—
Open weights & licence
Proprietary (proprietary)
Open weights (kimi-k3)
Kimi K3 allows independent hosting or local deployment
Provider & reseller market
Anthropic · 11 provider offers
Moonshot AI · 25 provider offers (4.73× spread)
—
When to Choose Claude Opus 5
Higher measured general capability (1502.5 Elo on human evaluation).
Direct integration with Anthropic tooling and API features.
Risks when moving from Kimi K3 → Claude Opus 5:
Context window: 1,048,576 → 1,000,000 tokens.
Output limit: 943,718 → 128,000 tokens.
video input is not supported by the candidate.
When to Choose Kimi K3
Larger context window (1,048,576 tokens) for long-document or repo-level context.
Higher maximum completion limit (943,718 tokens).
Open weights availability allows private self-hosting and on-premise execution.
Direct integration with Moonshot AI tooling and API features.
These settings are included in the share link. The fixed-request scenario and private evaluation data below are excluded.
A ↔ B
Neither model has both an equal-or-higher measured score and an equal-or-lower estimated price in this pair. Retaining your current model is a valid outcome.
Estimated blend: 75% input, 25% output; 0% cached input. Base context tier. Prompt length selects the billing tier. An unlisted cache-read rate uses that tier’s full input rate in this blend; missing required input or output rates prevent an estimate. The fixed-request estimate below validates actual context and output limits and requires a published cache-read rate when cache hits are assumed.
What changes between these models
Quality first, then estimated price. LMArena scores are human-preference measurements, not a benchmark of your application. A missing score is unrated.
Claude Opus 5 · Meets the stated model requirements
Kimi K3 · Meets the stated model requirements
Material differences and unknown evidence. Deltas compare each model with model A. Unknown facts remain visible.
Provider counts and precision flags describe catalogue offers. They do not establish the precision, availability, region, tool behaviour or limits of your chosen endpoint. Open each model’s provider table before switching.
Rates below are USD per 1M tokens. A threshold selects that whole input/output rate pair.
Input-token threshold
Input
Output
Cached input
Base, up to and including first threshold
$0.73
$10
$0.55
Migration preflight · compare each candidate with model A
Keeping Claude Opus 5 is a valid decision. No pairwise comparison certifies a drop-in replacement.
Claude Opus 5 → Kimi K3
Known loss or failed requirement
file input is not supported by the candidate.
Provider endpoint, serving precision, availability and task success need your own verification. Catalogue model capabilities do not certify an endpoint.
Private to this tab unless you save locally or explicitly export private details. These are estimates, not observed invoices. Cross-model token counts and task success are assumptions.
0.1 extra attempts means 10 extra full attempts per 100 requests. Cache writes, tool charges, taxes and unlisted charges are excluded.
Claude Opus 5Estimated total: $22.5 1,000 full attempts · base rates
Kimi K3Estimated total: $6.46 1,000 full attempts · base rates
Prompt and output sensitivity · sampled scenarios
Every point recalculates the entire request shape. Tier-boundary samples include one token below, at and above each threshold. Ordering between samples is not guaranteed. Lowest known cost excludes unknown estimates and is not a replacement recommendation.
Vary input; hold output, requests, cache and retries fixed.
Input tokens
Claude Opus 5
Kimi K3
Coverage
2,000
$22.5
$6.46Lowest known
All computed
4,096
$32.98
$7.99008Lowest known
All computed
32,768
$176.34
$28.92064Lowest known
All computed
131,072
$667.86
$100.68256Lowest known
All computed
Vary output; hold input, requests, cache and retries fixed.
Output tokens
Claude Opus 5
Kimi K3
128
$13.2
$2.74
2,048
$61.2
$21.94
8,192
$214.8
$83.38
Bring your observed evaluation results
JSON is parsed locally. Prompts, filenames, individual responses and extra fields are not retained. Import only aggregate measurements for selected models. Task/version labels do not establish that two evaluations used the same dataset.
Use the exact catalogue ID. Replace the example values with observed measurements. Omit costUsd or latencyMs when they are unknown. No public score is inferred from these observations.
Keep the decision and its evidence
A portable record retains selected facts, complete tier ladders, public requirements and the publication manifest. It also embeds the full permitted public catalogue to verify the input artifact checksum. Files are larger for this reason (up to 2 MB); local storage is limited to 12 records. Team review is local to this browser; there is no hosted collaboration.
Saving is opt-in and includes private review fields. Shared comparison links never include them. Version 1 Check references remain separate and are not overwritten or guessed into this format.
Saved local decisions · 0
No version 2 decision records are stored in this browser.
Questions this page answers
Is Claude Opus 5 a better-and-cheaper replacement for Kimi K3?
Neither model has both an equal-or-higher measured score and an equal-or-lower estimated price in this pair. Retaining your current model is a valid outcome.
Which model is higher rated: Claude Opus 5 or Kimi K3?
Claude Opus 5 scores higher on LMArena general (1502.5 ±3.7) compared to Kimi K3 (1475.6 ±4.6), a margin of 26.9 Elo points. The measured confidence intervals do not overlap, demonstrating a statistically significant preference lead on human evaluations.
Which model is more cost-effective: Claude Opus 5 or Kimi K3?
On a standard balanced workload (3 prompt tokens per 1 generated token), Kimi K3 costs $3.05 (price under confirmation since 2026-10-13) per 1M tokens versus $10.00 for Claude Opus 5. Claude Opus 5 is approximately 3.3× the price of Kimi K3. Base input rates are $5.00 for Claude Opus 5 and $0.730 for Kimi K3; base output rates are $25.00 for Claude Opus 5 and $10.00 for Kimi K3.
How do their context windows and generation limits compare?
Claude Opus 5 provides a 1,000,000-token context window with a maximum output limit of 128,000 tokens. Kimi K3 provides a 1,048,576-token context window with a maximum output of 943,718 tokens.
What capabilities are lost when switching between Claude Opus 5 and Kimi K3?
Switching from Claude Opus 5 to Kimi K3 involves: file input is not supported by the candidate. Conversely, moving from Kimi K3 to Claude Opus 5 involves: Context window: 1,048,576 → 1,000,000 tokens; Output limit: 943,718 → 128,000 tokens; video input is not supported by the candidate. Run test suites on your specific prompt templates and tool declarations before cutting over production traffic.
Can Claude Opus 5 or Kimi K3 be self-hosted or deployed privately?
Kimi K3 provides open weights, enabling self-hosting on private GPU infrastructure, local quantization, and private data pipelines. Managed inference is also offered across third-party API providers (11 for Claude Opus 5, 25 for Kimi K3).
What is included in this comparison?
Accepted model capabilities, context and output limits, complete price-tier ladders, independent LMArena measurements and missing evidence. Provider endpoint precision and application success still need verification.
Can I compare a different workload or keep a decision record?
Yes. Change the public workload, prompt length and requirements in the comparison workspace. Fixed-request scenarios, aggregate evaluations and review notes stay local unless explicitly exported.
