GPT-5.3 Codex Spark vs MiMo-V2.6-Pro-UltraSpeed
MiMo-V2.6-Pro-UltraSpeed comes out ahead, 44 to 38 on our weighted score, though GPT-5.3 Codex Spark is 11% cheaper per token.
OpenAIGPT-5.3 Codex Spark
38/100- ECI—
- Price$1.75 / $14.00
- Context128K
- Our pick
XiaomiMiMo-V2.6-Pro-UltraSpeed
44/100- ECI—
- Price$4.35 / $8.70
- Context1.05M
Add a model
Make it a three-way comparison.
MiMo-V2.6-Pro-UltraSpeed is our pick
MiMo-V2.6-Pro-UltraSpeed is the better all-round choice, scoring 44/100 against GPT-5.3 Codex Spark (38). It leads on context window. GPT-5.3 Codex Spark 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 priceGPT-5.3 Codex SparkGPT-5.3 Codex Spark $4.81 · MiMo-V2.6-Pro-UltraSpeed $5.44 per 1M tokens (3:1 blend)
- Longest contextMiMo-V2.6-Pro-UltraSpeedMiMo-V2.6-Pro-UltraSpeed 1,048,576 · GPT-5.3 Codex Spark 128,000 tokens
- Widest inputsMiMo-V2.6-Pro-UltraSpeedGPT-5.3 Codex Spark: Text, Images, PDFs · MiMo-V2.6-Pro-UltraSpeed: Text, Images, Audio, Video
- Self-hostingMiMo-V2.6-Pro-UltraSpeedPublishes downloadable weights
| Measure | Weight | GPT-5.3 Codex Spark | MiMo-V2.6-Pro-UltraSpeed |
|---|---|---|---|
| Price | 50% | 18 | 15 |
| Inputs & features | 30% | 80 | 80 |
| Context window | 20% | 24 | 61 |
| Overall | 100% | 38/100 | 44/100 |
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-5.3 Codex SparkOpenAI | MiMo-V2.6-Pro-UltraSpeedXiaomi |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $1.75 (best) | $4.35 |
| Output | $14.00 | $8.70 (best) |
| Cached input | $0.175 | $0.036 (best) |
| Blended (3:1) | $4.81 (best) | $5.44 |
| Long-context rate | Same rate | Same rate |
| Price source | Official OpenAI API | Official Xiaomi API |
| Limits | ||
| Context window | 128,000 tokens | 1,048,576 tokens (best) |
| Max output | 32,000 tokens | 131,072 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | Yes | No |
| Audio | No | Yes |
| Video | No | Yes |
| Reasoning | Yeslow · medium · high · xhigh | Yes |
| Tool calling | Yes | Yes |
| Structured output | Yes | No |
| Availability | ||
| Weights | Proprietary | Open |
| API model ID | gpt-5.3-codex-spark | mimo-v2.6-pro-ultraspeed |
| API providers | 1 | 9 (best) |
| Released | Feb 5, 2026 | Sep 21, 2026 |
| Knowledge cutoff | Aug 31, 2025 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.3 Codex Spark$45.50
- MiMo-V2.6-Pro-UltraSpeed$60.90
Which should you choose?
Which is better: GPT-5.3 Codex Spark or MiMo-V2.6-Pro-UltraSpeed?
MiMo-V2.6-Pro-UltraSpeed is the better all-round choice, scoring 44/100 against GPT-5.3 Codex Spark (38). It leads on context window. GPT-5.3 Codex Spark 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, GPT-5.3 Codex Spark or MiMo-V2.6-Pro-UltraSpeed?
GPT-5.3 Codex Spark is cheaper at $1.75 input / $14.00 output per million tokens (official OpenAI API price). MiMo-V2.6-Pro-UltraSpeed costs $4.35 input / $8.70 output per million tokens (official Xiaomi API price). At a typical mix of three input tokens to one output token, that is $4.81 per million tokens for GPT-5.3 Codex Spark versus $5.44 for MiMo-V2.6-Pro-UltraSpeed (1.1× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. GPT-5.3 Codex Spark has not been scored yet and MiMo-V2.6-Pro-UltraSpeed has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.3 Codex Spark and MiMo-V2.6-Pro-UltraSpeed 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?
MiMo-V2.6-Pro-UltraSpeed has the largest context window at 1,048,576 tokens, against 128,000 for GPT-5.3 Codex Spark. Maximum output per response: GPT-5.3 Codex Spark up to 32,000, MiMo-V2.6-Pro-UltraSpeed up to 131,072 tokens.
Which can read images, PDFs, audio or video?
GPT-5.3 Codex Spark accepts text, images and PDFs; MiMo-V2.6-Pro-UltraSpeed accepts text, images, audio and video. MiMo-V2.6-Pro-UltraSpeed handles the widest range of inputs.
Are any of these open source?
MiMo-V2.6-Pro-UltraSpeed publishes its weights and can be self-hosted; GPT-5.3 Codex Spark is proprietary.
Which is newer?
MiMo-V2.6-Pro-UltraSpeed is the newest, released Sep 21, 2026. GPT-5.3 Codex Spark came out Feb 5, 2026. Knowledge cutoff: GPT-5.3 Codex Spark Aug 31, 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.
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