Capability
Unranked
field median 58.1
Not eligible for a public rank
Mellum2-12B-A2.5B-Thinking
Released May 28, 2026 — see all recent releases
Decision reading
Mellum2-12B-A2.5B-Thinking is tracked, but not publicly ranked yet. The profile exposes 6 sourced benchmark rows and leaves unsupported fields blank until a published record exists.
Data as of September 4, 2026 · How the score is built
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Strongest published evidence
Agentic ranks #76. Particularly useful for coding agents, browser research, and computer-use workflows.
Validate before choosing
6 published rows leave some tracked benchmark slots empty. No comparable first-party API token rate is published.
Decision snapshot
Each value carries a field reference instead of floating alone. Markers compare this model with the current ranked and priced catalog; they are not absolute quality thresholds.
Price
Not listed
input median $1
No comparable first-party hosted token rate
Speed
Not measured
field median 92 tok/s
Time to first token not measured
Context
128Ktokens
field median 256,000
Reported for this model; direct source link not stored
How much of this is verified
Coverage is split by category so a strong number never hides a thin evidence base. Verified means the row is tied to a published source; provisional rows remain visible but separate.
- Agentic1/1 verified
- Coding1/1 verified
- ReasoningNot measured
- Knowledge3/3 verified
- MathNot measured
- MultilingualNot measured
- MultimodalNot measured
- Inst. Following1/1 verified
Verified sourceProvisionalNot measured
Spec sheet
Each documented value carries its source. Missing fields stay visible as not sourced or not published, rather than disappearing from the page.
- API model ID
- Not published
- Context window
- 128K
- Maximum output
- Not sourced yet
- Knowledge cutoff
- Not sourced yet
- Input modalities
- Not sourced yet
- Output modalities
- Not sourced yet
- Parameters
- 12B total · 2.5B active · MOE
- Availability
- Not sourced yet
- Cloud regions
- Not tracked yet
- Lifecycle
- Current
- API capabilities
- Tool calling, structured outputs, and batch support are not tracked yet
- Prompt caching
- Not documented in the pricing record
- Self-host
- Open weights available; hardware estimate not sourced
- Rate limits
- Not tracked yet
Deployment options
Self-host and provider-specific paths stay separate from benchmark evidence so operating constraints are visible before a score becomes the whole decision.
Published weights are available, but BenchLM does not yet have a sourced parameter and VRAM profile for this exact model. Hardware cost estimates stay unavailable until that sizing record is complete.
Estimate VRAM from known parametersCategory score record
Scores and ranks appear only where published evidence can be displayed. The table keeps the score, weight, cohort, and evidence state together.
| Category | Score | Rank | Percentile | Weight | Benchmarks | Evidence |
|---|---|---|---|---|---|---|
| AgenticRank #76 of 151Percentile 50thWeight 22%1 benchmarkVerified | 48.3 | #76 of 151 | 50th | 22% | 1 benchmark | Verified |
| CodingWeight 20%1 benchmarkVerified | Score pending | Not ranked | Not available | 20% | 1 benchmark | Verified |
| ReasoningWeight 17%0 benchmarksNot measured | Not measured | Not ranked | Not available | 17% | 0 benchmarks | Not measured |
| KnowledgeRank #96 of 181Percentile 47thWeight 12%3 benchmarksVerified | 48.8 | #96 of 181 | 47th | 12% | 3 benchmarks | Verified |
| MathWeight 5%0 benchmarksNot measured | Not measured | Not ranked | Not available | 5% | 0 benchmarks | Not measured |
| MultilingualWeight 7%0 benchmarksNot measured | Not measured | Not ranked | Not available | 7% | 0 benchmarks | Not measured |
| MultimodalWeight 12%0 benchmarksNot measured | Not measured | Not ranked | Not available | 12% | 0 benchmarks | Not measured |
| Inst. FollowingWeight 5%1 benchmarkVerified | Score pending | Not ranked | Not available | 5% | 1 benchmark | Verified |
Benchmark ledger
Coding opens by default. The marker compares each value with the best source-verified result in the catalog; provisional leaders do not set the reference. Expand the remaining categories for every published row.
Coding1 row
| Benchmark | Score | Versus best verified row | Gap | Weight | Evidence |
|---|---|---|---|---|---|
| LiveCodeBench v6 | Score69.9% | Versus best verified row Best verified: Sakana Fugu-Ultra · 93.2% | Gap23.3 behind | WeightDisplay only | Provider exact |
Agentic1 row
| Benchmark | Score | Versus best verified row | Gap | Weight | Evidence |
|---|---|---|---|---|---|
| BFCL v4Berkeley Function Calling Leaderboard v4 | Score45.6% | Versus best verified row Best verified: Qwen3.7 Max · 75.0% | Gap29.4 behind | WeightDisplay only | Provider exact |
Knowledge3 rows
| Benchmark | Score | Versus best verified row | Gap | Weight | Evidence |
|---|---|---|---|---|---|
| GPQAGraduate-Level Google-Proof Q&A | Score57.6% | Versus best verified row Best verified: GPT-6 Astra · 96% | Gap38.4 behind | WeightWeighted 7% | Provider exact |
| MMLU-Redux | Score86.2% | Versus best verified row Best verified: Qwen3.7 Max · 95% | Gap8.8 behind | WeightDisplay only | Provider exact |
| GPQA-DGPQA Diamond | Score57.6% | Versus best verified row Best verified: GPT-6 Astra · 96.0% | Gap38.4 behind | WeightDisplay only | Provider exact |
Inst. Following1 row
| Benchmark | Score | Versus best verified row | Gap | Weight | Evidence |
|---|---|---|---|---|---|
| IFEvalInstruction-Following Eval | Score76.5% | Versus best verified row Best verified: Qwen3.5-27B · 95% | Gap18.5 behind | WeightDisplay only | Provider exact |
Lineage
The sequence follows explicit supersedes links. A successor's displayed score stays at least 0.1 points above its predecessor; raw benchmark rows do not move. Scores and prices remain blank when the corresponding public row or first-party rate is unavailable.
May 28, 2026 · you are here
Mellum2-12B-A2.5B-ThinkingNot publicly ranked · Price not listed
Thinking
How to read this profile
The visual layer above carries the decisions. These notes preserve the model, ranking, coverage, and family context behind the numbers.
We track Mellum2-12B-A2.5B-Thinking, but the public leaderboard excludes this profile until enough non-generated benchmark coverage is available. Only published rows appear above.
Mellum2-12B-A2.5B-Thinking is a open weight model with a 128K context window. It uses an explicit reasoning mode, which can improve complex problem solving while adding latency and token use.
Official exact-value snapshot from the JetBrains Mellum2-12B-A2.5B-Thinking Hugging Face model card and Mellum2 technical report. BenchLM maps the self-reported post-training evaluation rows that match existing schema keys and stores LiveCodeBench v6 on the standard LiveCodeBench lane for consistency with other provider v6 tables.
Mellum2-12B-A2.5B-Thinking sits in the Mellum2 12B-A2.5B family with Mellum2-12B-A2.5B-Instruct. 6 of 422 tracked benchmark slots currently have displayable evidence. Missing categories stay blank.
Its strongest eligible category is Agentic at #76, while its lowest eligible position is Knowledge at #96. particularly useful for coding agents, browser research, and computer-use workflows.
Radar
Full release historyMellum2-12B-A2.5B-Thinking release history
Mellum2 12B-A2.5B released
JetBrains · Model release
Source confirmed
Radar confirmed these at the source. Already tracking Mellum2-12B-A2.5B-Thinking? See the free Radar Brief for what changes next.
Frequently asked questions
How does Mellum2-12B-A2.5B-Thinking perform overall in AI benchmarks?
Mellum2-12B-A2.5B-Thinking has 6 source-displayable benchmark rows, but it does not qualify for a public overall rank. The available rows remain visible by category without being converted into a site-wide score. Missing evidence stays blank instead of being estimated from an earlier model.
Is Mellum2-12B-A2.5B-Thinking good for knowledge and understanding?
Mellum2-12B-A2.5B-Thinking ranks #96 out of 181 eligible models for knowledge and understanding, with a public category score of 48.8/100. Higher-ranked alternatives are available for workloads where this category decides the choice. Check the underlying rows before treating the aggregate as a workload guarantee.
Is Mellum2-12B-A2.5B-Thinking good for coding and programming?
Mellum2-12B-A2.5B-Thinking has source-displayable benchmark coverage for coding and programming, but the public category table does not assign it a rank there. The individual rows remain available for inspection. A missing category position means the evidence threshold was not met; it does not convert the model's unmeasured work into a zero.
Is Mellum2-12B-A2.5B-Thinking good for agentic tool use and computer tasks?
Mellum2-12B-A2.5B-Thinking ranks #76 out of 151 eligible models for agentic tool use and computer tasks, with a public category score of 48.3/100. Higher-ranked alternatives are available for workloads where this category decides the choice. Check the underlying rows before treating the aggregate as a workload guarantee.
Is Mellum2-12B-A2.5B-Thinking good for instruction following?
Mellum2-12B-A2.5B-Thinking has source-displayable benchmark coverage for instruction following, but the public category table does not assign it a rank there. The individual rows remain available for inspection. A missing category position means the evidence threshold was not met; it does not convert the model's unmeasured work into a zero.
Is Mellum2-12B-A2.5B-Thinking open source?
Mellum2-12B-A2.5B-Thinking is an open-weight model from JetBrains. Its weights can be downloaded for local or hosted deployment, subject to the published license. Open weight does not automatically mean open source: training data and training code may remain private, and commercial restrictions can still apply.
Which sibling models are related to Mellum2-12B-A2.5B-Thinking?
Mellum2-12B-A2.5B-Thinking belongs to the Mellum2 12B-A2.5B family. Related tracked variants include Mellum2-12B-A2.5B-Instruct. A sibling link indicates shared lineage or a documented configuration relationship; it does not mean the variants have identical pricing, context limits, benchmark evidence, or deployment behavior. Compare before switching.
Does Mellum2-12B-A2.5B-Thinking have full benchmark coverage on BenchLM?
No. Mellum2-12B-A2.5B-Thinking currently has 6 source-displayable rows across 422 tracked benchmark slots. The profile exposes published, non-generated evidence and leaves missing categories blank until an exact evaluation is available. Coverage describes how much was measured; it is not a penalty added to an individual benchmark result.
What is the context window size of Mellum2-12B-A2.5B-Thinking?
Mellum2-12B-A2.5B-Thinking has a reported context window of 128K in the exact-model catalog record. The value stays visible, but the profile marks its source link as unavailable instead of presenting it as directly documented. Maximum output length remains separate because providers often publish a different limit.
Compare Mellum2-12B-A2.5B-Thinking with every tracked model410 comparisons
Last updated September 4, 2026. Runtime fields remain blank until a sourced snapshot exists.
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