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Model comparison

GPT-5.3 Codex vs MiMo-V2.5

Data verified

Head-to-head evidence from 4 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

66.69/100
Margin
8.1pts
← winning
Xiaomi
58.62/100
2 category wins0 category wins

Public leaderboard positions: GPT-5.3 Codex #26 (Supported); MiMo-V2.5 #62 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.3 Codex and MiMo-V2.5 share 4 comparable benchmark results. 2 of 8 categories are comparable. 17 results are unique to GPT-5.3 Codex; 7 to MiMo-V2.5.

Updated July 21, 2026
Shared results
4
GPT-5.3 Codex only
17
MiMo-V2.5 only
7
Comparable categories
2 / 8

Pick GPT-5.3 Codex if you want the stronger benchmark profile. MiMo-V2.5 only becomes the better choice if you need the larger 1M context window.

Confidence note. This is a partial-evidence comparison with 4 shared benchmark results across 3 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

GPT-5.3 Codex is clearly ahead on the BenchAlign aggregate, 66.69 to 58.62. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.3 Codex's sharpest advantage is in coding, where it averages 67.2 against 56.1. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 77.3% to 65.8%.

MiMo-V2.5 gives you the larger context window at 1M, compared with 400K for GPT-5.3 Codex.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for GPT-5.3 Codex and MiMo-V2.5
CategoryGPT-5.3 CodexΔMiMo-V2.5
CodingGPT-5.3 Codex67.2Margin 11.1MiMo-V2.556.1
AgenticGPT-5.3 Codex71.4Margin 5.6MiMo-V2.565.8
MultimodalGPT-5.3 CodexNot measuredMarginNo overlapMiMo-V2.579.0

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · GPT-5.3 CodexB · MiMo-V2.5
  1. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 77.3%B 65.8%
    Winner: GPT-5.3 CodexΔ 11.5
    Terminal-Bench 2.0: GPT-5.3 Codex scored 77.3%; MiMo-V2.5 scored 65.8%. GPT-5.3 Codex wins this benchmark.
  2. SWE-bench Pro

    Coding
    Source ↗
    A 56.8%B 56.1%
    Winner: GPT-5.3 CodexΔ 0.7
    SWE-bench Pro: GPT-5.3 Codex scored 56.8%; MiMo-V2.5 scored 56.1%. GPT-5.3 Codex wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricGPT-5.3 CodexMiMo-V2.5Comparison
Input / output priceUSD per 1M tokensGPT-5.3 Codex$1.75 input / $14 outputMiMo-V2.5Not availableA complete price comparison is not available.
Generation speedtokens per secondGPT-5.3 Codex79 tok/sMiMo-V2.5Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-5.3 Codex88.26 sMiMo-V2.5Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-5.3 Codex400KMiMo-V2.51MMiMo-V2.5 lists the larger context window.

Benchmark Deep Dive

AgenticGPT-5.3 Codex wins
BenchmarkGPT-5.3 CodexMiMo-V2.5Result
Terminal-Bench 2.0Source 77.3%65.8%GPT-5.3 Codex leads
OSWorld-VerifiedSource 64.7%Not comparable
τ²-bench resultsSource 86%Not comparable
Gert LabsSource 57.47%46.89%GPT-5.3 Codex leads
JobBenchSource 33.7%Not comparable
Claw-EvalSource 62.3%Not comparable
MM-ClawBenchSource 23.8%Not comparable
ResearchClawBenchSource 16.9%Not comparable
CodingGPT-5.3 Codex wins
BenchmarkGPT-5.3 CodexMiMo-V2.5Result
SWE-bench VerifiedSource 85%Not comparable
SWE-bench ProSource 56.8%56.1%GPT-5.3 Codex leads
SWE-RebenchSource 58.2%Not comparable
Vibe Code BenchSource 61.77%Not comparable
AA-SciCodeSource 53.2%Not comparable
Terminal-Bench 2.0Source 65.8%Not comparable
Reasoning
BenchmarkGPT-5.3 CodexMiMo-V2.5Result
AA-LCRSource 74.0%Not comparable
CritPtSource 16.9%Not comparable
Knowledge
BenchmarkGPT-5.3 CodexMiMo-V2.5Result
Artificial Analysis Intelligence IndexSource 44.3%Not comparable
AA-GPQA DiamondSource 91.5%Not comparable
AA-HLESource 39.9%Not comparable
AA-Omniscience IndexSource 9.9%Not comparable
AA-Omniscience AccuracySource 51.8%Not comparable
AA-Omniscience Hallucination RateSource 86.9%Not comparable
Multimodal
BenchmarkGPT-5.3 CodexMiMo-V2.5Result
AA-MMMU-ProSource 78.5%Not comparable
Design Arena WebsiteSource 11931291MiMo-V2.5 leads
Video-MME (with subtitle)Source 87.7%Not comparable
CharXivSource 81%Not comparable
MMMU-ProSource 77.9%Not comparable
Inst. Following
BenchmarkGPT-5.3 CodexMiMo-V2.5Result
AA-IFBenchSource 75.4%Not comparable
Frequently Asked Questions (3)

Which is better, GPT-5.3 Codex or MiMo-V2.5?

GPT-5.3 Codex is ahead on BenchLM's BenchAlign leaderboard, 66.69 to 58.62. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 77.3% and 65.8%.

Which is better for coding, GPT-5.3 Codex or MiMo-V2.5?

GPT-5.3 Codex has the edge for coding in this comparison, averaging 67.2 versus 56.1. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.3 Codex or MiMo-V2.5?

GPT-5.3 Codex has the edge for agentic tasks in this comparison, averaging 71.4 versus 65.8. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

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Last updated: July 21, 2026

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