GPT-5.1 Codex mini vs Grok 4.20 (Non-Reasoning) vs MiMo-V2-Pro
Too close to call on our weighted score (GPT-5.1 Codex mini 54, Grok 4.20 (Non-Reasoning) 52, MiMo-V2-Pro 42). The right pick depends on what you value most.
OpenAIGPT-5.1 Codex mini
54/100- ECI—
- Price$0.25 / $2.00
- Context400K
xAIGrok 4.20 (Non-Reasoning)
52/100- ECI—
- Price$1.25 / $2.50
- Context1M
XiaomiMiMo-V2-Pro
42/100- ECI—
- Price$1.00 / $3.00
- Context1.05M
Too close to call
It is close. Our weighted score puts them within 2 points (GPT-5.1 Codex mini 54/100, Grok 4.20 (Non-Reasoning) 52/100, MiMo-V2-Pro 42/100), so choose by what matters most for your work: GPT-5.1 Codex mini on price and MiMo-V2-Pro for long inputs. 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 priceGPT-5.1 Codex miniGPT-5.1 Codex mini $0.688 · MiMo-V2-Pro $1.50 · Grok 4.20 (Non-Reasoning) $1.56 per 1M tokens (3:1 blend)
- Longest contextMiMo-V2-ProMiMo-V2-Pro 1,048,576 · Grok 4.20 (Non-Reasoning) 1,000,000 · GPT-5.1 Codex mini 400,000 tokens
- Widest inputsGrok 4.20 (Non-Reasoning)GPT-5.1 Codex mini: Text, Images · Grok 4.20 (Non-Reasoning): Text, Images, PDFs · MiMo-V2-Pro: Text
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | GPT-5.1 Codex mini | Grok 4.20 (Non-Reasoning) | MiMo-V2-Pro |
|---|---|---|---|---|
| Price | 50% | 55 | 39 | 40 |
| Inputs & features | 30% | 60 | 70 | 35 |
| Context window | 20% | 44 | 60 | 61 |
| Overall | 100% | 54/100 | 52/100 | 42/100 |
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 | GPT-5.1 Codex miniOpenAI | Grok 4.20 (Non-Reasoning)xAI | MiMo-V2-ProXiaomi |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.25 (best) | $1.25 | $1.00 |
| Output | $2.00 (best) | $2.50 | $3.00 |
| Cached input | — | $0.20 | — |
| Blended (3:1) | $0.688 (best) | $1.56 | $1.50 |
| Long-context rate | Same rate | Over 200K: $2.50 / $5.00 | Same rate |
| Price source | Median of 16 providers | Official xAI API | Median of 1 providers |
| Limits | |||
| Context window | 400,000 tokens | 1,000,000 tokens | 1,048,576 tokens (best) |
| Max output | 128,000 tokens | 30,000 tokens | 131,072 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | No |
| PDFs | No | Yes | No |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yes | No | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | Yes | No |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | — | grok-4.20-0309-non-reasoning | — |
| API providers | 16 (best) | 13 | 2 |
| Released | Nov 13, 2025 | Mar 9, 2026 | Mar 18, 2026 |
| Knowledge cutoff | Sep 30, 2024 | — | Dec 2024 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.1 Codex mini$6.50
- Grok 4.20 (Non-Reasoning)$17.50
- MiMo-V2-Pro$16.00
Which should you choose?
Which is better: GPT-5.1 Codex mini, Grok 4.20 (Non-Reasoning) or MiMo-V2-Pro?
It is close. Our weighted score puts them within 2 points (GPT-5.1 Codex mini 54/100, Grok 4.20 (Non-Reasoning) 52/100, MiMo-V2-Pro 42/100), so choose by what matters most for your work: GPT-5.1 Codex mini on price and MiMo-V2-Pro for long inputs. 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, GPT-5.1 Codex mini, Grok 4.20 (Non-Reasoning) or MiMo-V2-Pro?
GPT-5.1 Codex mini is cheaper at $0.25 input / $2.00 output per million tokens (median across 16 API providers). MiMo-V2-Pro costs $1.00 input / $3.00 output per million tokens (median across 1 API provider); Grok 4.20 (Non-Reasoning) costs $1.25 input / $2.50 output per million tokens (official xAI API price). At a typical mix of three input tokens to one output token, that is $0.688 per million tokens for GPT-5.1 Codex mini versus $1.50 for MiMo-V2-Pro (2.2× as much) and $1.56 for Grok 4.20 (Non-Reasoning) (2.3× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. GPT-5.1 Codex mini has not been scored yet, Grok 4.20 (Non-Reasoning) has not been scored yet and MiMo-V2-Pro has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.1 Codex mini, Grok 4.20 (Non-Reasoning) and MiMo-V2-Pro yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three support tool calling for agent workflows.
Which has the bigger context window?
MiMo-V2-Pro has the largest context window at 1,048,576 tokens, against 1,000,000 for Grok 4.20 (Non-Reasoning) and 400,000 for GPT-5.1 Codex mini. Maximum output per response: GPT-5.1 Codex mini up to 128,000, Grok 4.20 (Non-Reasoning) up to 30,000, MiMo-V2-Pro up to 131,072 tokens.
Which can read images, PDFs, audio or video?
GPT-5.1 Codex mini accepts text and images; Grok 4.20 (Non-Reasoning) accepts text, images and PDFs; MiMo-V2-Pro accepts text. Grok 4.20 (Non-Reasoning) handles the widest range of inputs.
Are any of these open source?
No. GPT-5.1 Codex mini, Grok 4.20 (Non-Reasoning) and MiMo-V2-Pro are proprietary and only available through APIs and apps.
Which is newer?
MiMo-V2-Pro is the newest, released Mar 18, 2026. Grok 4.20 (Non-Reasoning) came out Mar 9, 2026; GPT-5.1 Codex mini came out Nov 13, 2025. Knowledge cutoff: GPT-5.1 Codex mini Sep 30, 2024, MiMo-V2-Pro Dec 2024.
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 Nov 2, 2026.
