Apertus 8B vs Grok 4.1 Fast
Grok 4.1 Fast comes out ahead, 71 to 56 on our weighted score, though Apertus 8B is 2.2× cheaper per token.
Swiss AI
Apertus 8B
56/100- ECI—
- Price$0.10 / $0.20
- Context66K
- Our pick
xAIGrok 4.1 Fast
71/100- ECI—
- Price$0.20 / $0.50
- Context2M
Add a model
Make it a three-way comparison.
Grok 4.1 Fast is our pick
Grok 4.1 Fast is the better all-round choice, scoring 71/100 against Apertus 8B (56). It leads on inputs & features and context window. Apertus 8B wins on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceApertus 8BApertus 8B $0.125 · Grok 4.1 Fast $0.275 per 1M tokens (3:1 blend)
- Longest contextGrok 4.1 FastGrok 4.1 Fast 2,000,000 · Apertus 8B 65,536 tokens
- Widest inputsGrok 4.1 FastApertus 8B: Text · Grok 4.1 Fast: Text, Images
- Self-hostingApertus 8BPublishes downloadable weights (Apache-2.0)
| Measure | Weight | Apertus 8B | Grok 4.1 Fast |
|---|---|---|---|
| Price | 50% | 93 | 76 |
| Inputs & features | 30% | 25 | 60 |
| Context window | 20% | 12 | 72 |
| Overall | 100% | 56/100 | 71/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Apertus 8BSwiss AI | Grok 4.1 FastxAI |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $0.10 (best) | $0.20 |
| Output | $0.20 (best) | $0.50 |
| Cached input | — | — |
| Blended (3:1) | $0.125 (best) | $0.275 |
| Long-context rate | Same rate | Same rate |
| Price source | Median of 1 providers | Median of 2 providers |
| Limits | ||
| Context window | 65,536 tokens | 2,000,000 tokens (best) |
| Max output | 8,192 tokens | 30,000 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | No | Yes |
| PDFs | No | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | No | No |
| Tool calling | Yes | Yes |
| Structured output | No | Yes |
| Availability | ||
| Weights | OpenApache-2.0 | Proprietary |
| API model ID | — | — |
| API providers | 1 | 2 (best) |
| Released | Sep 2, 2025 | Nov 19, 2025 |
| Knowledge cutoff | Sep 2025 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Apertus 8B$1.40
- Grok 4.1 Fast$3.00
Which should you choose?
Which is better: Apertus 8B or Grok 4.1 Fast?
Grok 4.1 Fast is the better all-round choice, scoring 71/100 against Apertus 8B (56). It leads on inputs & features and context window. Apertus 8B wins on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Apertus 8B or Grok 4.1 Fast?
Apertus 8B is cheaper at $0.10 input / $0.20 output per million tokens (median across 1 API provider). Grok 4.1 Fast costs $0.20 input / $0.50 output per million tokens (median across 2 API providers). At a typical mix of three input tokens to one output token, that is $0.125 per million tokens for Apertus 8B versus $0.275 for Grok 4.1 Fast (2.2× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Apertus 8B has not been scored yet and Grok 4.1 Fast has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Apertus 8B and Grok 4.1 Fast yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Grok 4.1 Fast has the largest context window at 2,000,000 tokens, against 65,536 for Apertus 8B. Maximum output per response: Apertus 8B up to 8,192, Grok 4.1 Fast up to 30,000 tokens.
Which can read images, PDFs, audio or video?
Apertus 8B accepts text; Grok 4.1 Fast accepts text and images. Grok 4.1 Fast handles the widest range of inputs.
Are any of these open source?
Apertus 8B publishes its weights (Apache-2.0) and can be self-hosted; Grok 4.1 Fast is proprietary.
Which is newer?
Grok 4.1 Fast is the newest, released Nov 19, 2025. Apertus 8B came out Sep 2, 2025. Knowledge cutoff: Apertus 8B Sep 2025.
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.
