GPT-5.4 Pro vs Claude Fable 5 vs Kimi K3
Too close to call on our weighted score (Kimi K3 65, Claude Fable 5 65, GPT-5.4 Pro 60). The right pick depends on what you value most.
OpenAIGPT-5.4 Pro
60/100- ECI159.1
- Price$30.00 / $180.00
- Context1.05M
AnthropicClaude Fable 5
65/100- ECI162.2
- Price$10.00 / $50.00
- Context1M
Moonshot AIKimi K3
65/100- ECI157.6
- Price$3.00 / $15.00
- Context1.05M
Too close to call
It is close. Our weighted score puts them within a point (Kimi K3 65/100, Claude Fable 5 65/100, GPT-5.4 Pro 60/100), so choose by what matters most for your work: Claude Fable 5 for raw capability and Kimi K3 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityClaude Fable 5Capabilities Index (ECI): Claude Fable 5 162.2 · GPT-5.4 Pro 159.1 · Kimi K3 157.6
- Lowest priceKimi K3Kimi K3 $6.00 · Claude Fable 5 $20.00 · GPT-5.4 Pro $67.50 per 1M tokens (3:1 blend)
- Longest contextGPT-5.4 Pro and Kimi K3GPT-5.4 Pro 1,050,000 · Kimi K3 1,048,576 · Claude Fable 5 1,000,000 tokens
- Widest inputsClaude Fable 5 and Kimi K3GPT-5.4 Pro: Text, Images · Claude Fable 5: Text, Images, PDFs · Kimi K3: Text, Images, Video
- Self-hostingKimi K3Publishes downloadable weights
| Measure | Weight | GPT-5.4 Pro | Claude Fable 5 | Kimi K3 |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 90 | 94 | 88 |
| Price | 25% | 0 | 0 | 13 |
| Inputs & features | 15% | 60 | 80 | 80 |
| Context window | 10% | 61 | 60 | 61 |
| Overall | 100% | 60/100 | 65/100 | 65/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.4 ProOpenAI | Claude Fable 5Anthropic | Kimi K3Moonshot AI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 159.1 | 162.2 (best) | 157.6 |
| ECI rank | #11 of 148 | #7 of 148 (best) | #13 of 148 |
| GPQA DiamondGraduate-level science questions | 94.6% (best) | 85.9% | 93.1% |
| FrontierMath Tiers 1–3Research-level mathematics | 82.5% | 87.0% (best) | 72.2% |
| OTIS Mock AIME 2024–2025Competition mathematics | — | 100% (best) | 97.2% |
| SimpleQA VerifiedShort factual questions | 46.3% | 70.7% (best) | 50.6% |
| Price per million tokens | |||
| Input | $30.00 | $10.00 | $3.00 (best) |
| Output | $180.00 | $50.00 | $15.00 (best) |
| Cached input | — | $1.00 | $0.30 (best) |
| Blended (3:1) | $67.50 | $20.00 | $6.00 (best) |
| Long-context rate | Over 272K: $60.00 / $270.00 | Same rate | Same rate |
| Price source | Official OpenAI API | Official Anthropic API | Official Moonshot AI API |
| Limits | |||
| Context window | 1,050,000 tokens (best) | 1,000,000 tokens | 1,048,576 tokens |
| Max output | 128,000 tokens | 128,000 tokens | 131,072 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | Yes | No |
| Audio | No | No | No |
| Video | No | No | Yes |
| Reasoning | Yesmedium · high · xhigh | Yeslow · medium · high · xhigh · max | Yeslow · high · max |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Open |
| API model ID | gpt-5.4-pro | claude-fable-5 | kimi-k3 |
| API providers | 16 | 38 | 68 (best) |
| Released | Mar 5, 2026 | Jun 9, 2026 | Jul 16, 2026 |
| Knowledge cutoff | Aug 31, 2025 | Jan 31, 2026 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.4 Pro$660.00
- Claude Fable 5$200.00
- Kimi K3$60.00
Which should you choose?
Which is better: GPT-5.4 Pro, Claude Fable 5 or Kimi K3?
It is close. Our weighted score puts them within a point (Kimi K3 65/100, Claude Fable 5 65/100, GPT-5.4 Pro 60/100), so choose by what matters most for your work: Claude Fable 5 for raw capability and Kimi K3 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-5.4 Pro, Claude Fable 5 or Kimi K3?
Kimi K3 is cheaper at $3.00 input / $15.00 output per million tokens (official Moonshot AI API price). Claude Fable 5 costs $10.00 input / $50.00 output per million tokens (official Anthropic API price); GPT-5.4 Pro costs $30.00 input / $180.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $6.00 per million tokens for Kimi K3 versus $20.00 for Claude Fable 5 (3.3× as much) and $67.50 for GPT-5.4 Pro (11× as much).
Which scores higher on benchmarks?
Claude Fable 5 scores higher on the Capabilities Index (ECI): Claude Fable 5 162.2 (#7 of 148), GPT-5.4 Pro 159.1 (#11 of 148) and Kimi K3 157.6 (#13 of 148). The confidence ranges of the top two overlap (159.6–166.1 vs 156.5–161.9), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.4 Pro 94.6%, Kimi K3 93.1%, Claude Fable 5 85.9%; FrontierMath Tiers 1–3 — Claude Fable 5 87.0%, GPT-5.4 Pro 82.5%, Kimi K3 72.2%; SimpleQA Verified — Claude Fable 5 70.7%, Kimi K3 50.6%, GPT-5.4 Pro 46.3%.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.4 Pro, Claude Fable 5 and Kimi K3 yet, so there is no like-for-like coding score. On overall capability, Claude Fable 5 leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.
Which has the bigger context window?
GPT-5.4 Pro and Kimi K3 have the largest context windows (1,050,000 and 1,048,576 tokens), against 1,000,000 for Claude Fable 5. Maximum output per response: GPT-5.4 Pro up to 128,000, Claude Fable 5 up to 128,000, Kimi K3 up to 131,072 tokens.
Which can read images, PDFs, audio or video?
GPT-5.4 Pro accepts text and images; Claude Fable 5 accepts text, images and PDFs; Kimi K3 accepts text, images and video. Claude Fable 5 handles the widest range of inputs.
Are any of these open source?
Kimi K3 publishes its weights and can be self-hosted; GPT-5.4 Pro and Claude Fable 5 is proprietary.
Which is newer?
Kimi K3 is the newest, released Jul 16, 2026. Claude Fable 5 came out Jun 9, 2026; GPT-5.4 Pro came out Mar 5, 2026. Knowledge cutoff: GPT-5.4 Pro Aug 31, 2025, Claude Fable 5 Jan 31, 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
