GPT-5.3-Codex vs MiMo-V2.6-Flash
Updated October 21, 2026. 10 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Pick MiMo-V2.6-Flash for coding: it scores 61.9 on the Vibe Coding Index against 29.5 for GPT-5.3-Codex.
Pick GPT-5.3-Codex when what matters is IOI (Vals AI) or ALE-Bench, where it leads.
- Shared results
- 10
- GPT-5.3-Codex only
- 24
- MiMo-V2.6-Flash only
- 56
- Like-for-like categories
- 4 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, four public coding benchmarks
MiMo-V2.6-Flash
MiMo-V2.6-Flash scores 61.9 against 29.5.
One benchmark behind each score
Intelligence
AA Intelligence Index
MiMo-V2.6-Flash
MiMo-V2.6-Flash leads, 37.9 against 32.5.
Same board, both measured
Web design
Design Arena: websites
No call
Only GPT-5.3-Codex has a Design Arena: websites result, 1163.
Directional only
General
Vals Index
No call
Only MiMo-V2.6-Flash has a Vals Index result, 54.8%.
Directional only
Long documents
Listed context window
MiMo-V2.6-Flash
MiMo-V2.6-Flash takes 1.05M tokens against 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
MiMo-V2.6-Flash
GPT-5.3-Codex $0.0088, MiMo-V2.6-Flash $0.0003 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5.3-Codex has the number, $0.59.
Directional only
At a glance
- Coding index
- GPT-5.3-Codex 29.5 from 1 benchmark, MiMo-V2.6-Flash 61.9 from 1 benchmark.
- Widest category
- Coding, 22.7 points apart on average over 7 shared benchmarks.
- Widest single gap
- LMArena WebDev: React: GPT-5.3-Codex 1395 against MiMo-V2.6-Flash 1648, 34.2 points apart on a 0 to 100 scale.
- Output price
- GPT-5.3-Codex $14.00 against MiMo-V2.6-Flash $0.28 per million output tokens, 50.0x apart.
- Context window
- GPT-5.3-Codex takes 400K tokens, MiMo-V2.6-Flash 1.05M.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | GPT-5.3-Codex | Bars | MiMo-V2.6-Flash | Ties |
|---|---|---|---|---|
| Coding | 2 | 5 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 1 | 0 | ||
| General | 1 | 0 | ||
| All shared boards | 4 | 6 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index25
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| LMArena WebDev | 1407 | 1634 | MiMo-V2.6-Flash |
| LiveCodeBench (Vals AI) | 87.3% | Not measured | Only GPT-5.3-Codex measured |
| SWE-bench Verified (Vals AI) | 78.0% | Not measured | Only GPT-5.3-Codex measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 24.2% | Only MiMo-V2.6-Flash measured |
| Vibe Code Bench (Vals AI) | 61.8% | 79.0% | MiMo-V2.6-Flash |
| Code migration (Vals AI) | Not measured | 40.9% | Only MiMo-V2.6-Flash measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only MiMo-V2.6-Flash measured |
| IOI (Vals AI) | 53.8% | 47.7% | GPT-5.3-Codex |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 76.4% | Only MiMo-V2.6-Flash measured |
| CyberBench (Vals AI) | Not measured | 75.4% | Only MiMo-V2.6-Flash measured |
| SciCode | Not measured | 51.3% | Only MiMo-V2.6-Flash measured |
| Terminal-Bench Hard (Artificial Analysis run) | 53.0% | Not measured | Only GPT-5.3-Codex measured |
| Terminal-Bench | 78.4% | Not measured | Only GPT-5.3-Codex measured |
| WeirdML | 79.3% | Not measured | Only GPT-5.3-Codex measured |
| ALE-Bench | 1655.2 | 1244.2 | GPT-5.3-Codex |
| LMArena Text: coding | Not measured | 1499 | Only MiMo-V2.6-Flash measured |
| LMArena Text: software and IT | Not measured | 1497 | Only MiMo-V2.6-Flash measured |
| LMArena WebDev: React | 1395 | 1648 | MiMo-V2.6-Flash |
| LMArena WebDev: HTML | 1422 | 1641 | MiMo-V2.6-Flash |
| LMArena WebDev: from an image | 1443 | 1596 | MiMo-V2.6-Flash |
| Neither model has a result on the other 18 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 32.5 | 37.9 | MiMo-V2.6-Flash |
| Epoch Capabilities Index | 157.1 | Not measured | Only GPT-5.3-Codex measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index17 boards, none shared
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1033 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: agents building full-stack apps | 983 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: agents building mobile apps | 1054 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: agents building Android apps | 1084 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: agents building Godot games | 1124 | Not measured | Only GPT-5.3-Codex measured |
| SREBench (Vals AI) | Not measured | 4.2% | Only MiMo-V2.6-Flash measured |
| Finance Agent (Vals AI) | Not measured | 56.3% | Only MiMo-V2.6-Flash measured |
| Tax Agent Bench (Vals AI) | Not measured | 28.5% | Only MiMo-V2.6-Flash measured |
| Legal Research Bench (Vals AI) | Not measured | 38.0% | Only MiMo-V2.6-Flash measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 13.3% | Only MiMo-V2.6-Flash measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 65.5% | Only MiMo-V2.6-Flash measured |
| BioMysteryBench (Vals AI) | Not measured | 69.3% | Only MiMo-V2.6-Flash measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 4.3% | Only MiMo-V2.6-Flash measured |
| Vals Science Index | Not measured | 31.7% | Only MiMo-V2.6-Flash measured |
| τ²-Bench Telecom | 86.0% | Not measured | Only GPT-5.3-Codex measured |
| METR time horizons | 74.5% | Not measured | Only GPT-5.3-Codex measured |
| Vending-Bench 2 | $5,940 | Not measured | Only GPT-5.3-Codex measured |
| Neither model has a result on the other 22 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| MysteryMechanism (Vals AI) | Not measured | 21.6% | Only MiMo-V2.6-Flash measured |
| GPQA Diamond (Artificial Analysis run) | 91.5% | Not measured | Only GPT-5.3-Codex measured |
| Humanity's Last Exam (Artificial Analysis run) | 42.5% | 35.1% | GPT-5.3-Codex |
| LMArena Text: hard prompts | Not measured | 1475 | Only MiMo-V2.6-Flash measured |
| LMArena Text: expert | Not measured | 1496 | Only MiMo-V2.6-Flash measured |
| LMArena Text: hard prompts in English | Not measured | 1493 | Only MiMo-V2.6-Flash measured |
| LMArena Vision: diagrams | Not measured | 1276 | Only MiMo-V2.6-Flash measured |
| LMArena Vision: homework | Not measured | 1283 | Only MiMo-V2.6-Flash measured |
| Neither model has a result on the other 13 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| ProofBench | Not measured | 63.0% | Only MiMo-V2.6-Flash measured |
| LMArena Text: math | Not measured | 1476 | Only MiMo-V2.6-Flash measured |
| LMArena Text: mathematical work | Not measured | 1478 | Only MiMo-V2.6-Flash measured |
| Neither model has a result on the other 10 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index5 boards, none shared
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| MedCode (Vals AI) | Not measured | 41.1% | Only MiMo-V2.6-Flash measured |
| LMArena Text: science | Not measured | 1462 | Only MiMo-V2.6-Flash measured |
| LMArena Text: medicine and healthcare | Not measured | 1439 | Only MiMo-V2.6-Flash measured |
| LMArena Text: legal and government | Not measured | 1441 | Only MiMo-V2.6-Flash measured |
| LMArena Text: business and finance | Not measured | 1454 | Only MiMo-V2.6-Flash measured |
| Neither model has a result on the other 12 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1163 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: UI components | 1137 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: game dev | 1162 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: data viz | 1164 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: 3D | 1008 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: all code categories | 1145 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: SVG | 1129 | Not measured | Only GPT-5.3-Codex measured |
| Design Arena: ASCII art | 1151 | Not measured | Only GPT-5.3-Codex measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| Vals Index | Not measured | 54.8% | Only MiMo-V2.6-Flash measured |
| Public Benefits Bench (Vals AI) | Not measured | 67.6% | Only MiMo-V2.6-Flash measured |
| SAGE (Vals AI) | Not measured | 43.5% | Only MiMo-V2.6-Flash measured |
| MedScribe (Vals AI) | Not measured | 85.3% | Only MiMo-V2.6-Flash measured |
| IFBench | 75.4% | Not measured | Only GPT-5.3-Codex measured |
| Long context reasoning (AA-LCR) | 83.3% | 74.3% | GPT-5.3-Codex |
| LMArena Text | Not measured | 1453 | Only MiMo-V2.6-Flash measured |
| LMArena Text: instruction following | Not measured | 1452 | Only MiMo-V2.6-Flash measured |
| LMArena Text: creative writing | Not measured | 1403 | Only MiMo-V2.6-Flash measured |
| LMArena Vision | Not measured | 1256 | Only MiMo-V2.6-Flash measured |
| LMArena Text: English | Not measured | 1476 | Only MiMo-V2.6-Flash measured |
| LMArena Text: non-English | Not measured | 1431 | Only MiMo-V2.6-Flash measured |
| LMArena Text: Chinese | Not measured | 1509 | Only MiMo-V2.6-Flash measured |
| LMArena Text: German | Not measured | 1458 | Only MiMo-V2.6-Flash measured |
| LMArena Text: Japanese | Not measured | 1359 | Only MiMo-V2.6-Flash measured |
| LMArena Text: Korean | Not measured | 1425 | Only MiMo-V2.6-Flash measured |
| LMArena Text: French | Not measured | 1480 | Only MiMo-V2.6-Flash measured |
| LMArena Text: Spanish | Not measured | 1453 | Only MiMo-V2.6-Flash measured |
| LMArena Text: Russian | Not measured | 1409 | Only MiMo-V2.6-Flash measured |
| LMArena Text: Polish | Not measured | 1455 | Only MiMo-V2.6-Flash measured |
| LMArena Text: multi-turn | Not measured | 1447 | Only MiMo-V2.6-Flash measured |
| LMArena Text: longer queries | Not measured | 1459 | Only MiMo-V2.6-Flash measured |
| LMArena Text: writing and language | Not measured | 1424 | Only MiMo-V2.6-Flash measured |
| LMArena Text: entertainment and media | Not measured | 1415 | Only MiMo-V2.6-Flash measured |
| LMArena Vision: English | Not measured | 1269 | Only MiMo-V2.6-Flash measured |
| LMArena Vision: reading text | Not measured | 1270 | Only MiMo-V2.6-Flash measured |
| LMArena Vision: creative writing | Not measured | 1231 | Only MiMo-V2.6-Flash measured |
| Neither model has a result on the other 19 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.3-Codex | MiMo-V2.6-Flash | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
MiMo-V2.6-Flash costs less
Repository review
50K input + 3K output tokens
MiMo-V2.6-Flash costs less
Agent loop
200K input + 10K output tokens
MiMo-V2.6-Flash costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | OpenAI GPT-5.3-Codex | Xiaomi MiMo-V2.6-Flash |
|---|---|---|
| Maker | OpenAI | Xiaomi |
| Weights | No public weights listed | Open weights |
| Released | February 24, 2026 | September 21, 2026 |
| Context window | 400K | 1.05M |
| Input $/Mtok | $1.75 | $0.14 |
| Output $/Mtok | $14.00 | $0.28 |
| Coding index | 29.5 | 61.9 |
| Independent measurements behind it | 1 | 1 |
| Cost per solved task | $0.59 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.3-Codex better than MiMo-V2.6-Flash for coding?
Pick MiMo-V2.6-Flash for coding: it scores 61.9 on the Vibe Coding Index against 29.5 for GPT-5.3-Codex. Pick GPT-5.3-Codex when what matters is IOI (Vals AI) or ALE-Bench, where it leads.
Which is cheaper, GPT-5.3-Codex or MiMo-V2.6-Flash?
GPT-5.3-Codex costs $1.75 per million input tokens and $14.00 per million output tokens; MiMo-V2.6-Flash costs $0.14 and $0.28. Cost per solved task is known for GPT-5.3-Codex only.
Which has the bigger context window, GPT-5.3-Codex or MiMo-V2.6-Flash?
MiMo-V2.6-Flash, with 1.05M tokens against 400K.
How many benchmarks is the GPT-5.3-Codex vs MiMo-V2.6-Flash comparison based on?
10 benchmarks have a result for both models as of October 21, 2026. GPT-5.3-Codex's coding index rests on 1 independent benchmark and MiMo-V2.6-Flash's on 1. Where only one model has a result, the page says so instead of naming a winner.