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GPT-6 Astra vs Mistral Medium 3.5 128B

Updated October 17, 2026. Rank says GPT-6 Astra is ahead. Price, access, and your workload can each overturn that. Public scores include evidence status and uncertainty.

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Decision reading

GPT-6 Astra has the higher public point estimate, 83.88 versus 33.62. Their conditional score ranges do not overlap. These ranges do not establish rank confidence. 1 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

Model A
OpenAI logo

OpenAI

83.88/100

Supported · Public rank #3

90% interval 79.4–88.3

Model B
Mistral logo

Mistral

33.62/100

Estimated · Public rank #162

Conditional range 19.3–48.0

Shared results
1
GPT-6 Astra only
39
Mistral Medium 3.5 128B only
6
Like-for-like categories
2 / 8
Supported: GPT-6 Astra · Estimated: Mistral Medium 3.5 128B. Conditional ranges do not establish rank confidence.How the comparison works

Which one for your work

Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.

  • Agentic work

    Tool use, computer use, and multi-step task completion

    GPT-6 Astra

    GPT-6 Astra has the higher public agentic point estimate, 74.8 to 19.8, with Supported evidence for both models. The conditional ranges do not establish rank confidence.

    Confidence: limited
  • Long documents

    Prompts that approach the documented context limit

    GPT-6 Astra

    GPT-6 Astra has the larger documented context window.

    Confidence: documented
  • Chat turn cost

    1K fresh input + 500 output tokens

    Mistral Medium 3.5 128B

    Mistral Medium 3.5 128B has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
Show secondary and unsupported calls
  • Cache-heavy agent loop cost

    200K cached + 20K fresh input + 10K output tokens

    Mistral Medium 3.5 128B

    Mistral Medium 3.5 128B has the lower estimated token cost for this stated workload. Mistral Medium 3.5 128B has no published cached-input rate, so cached tokens use its listed input rate.

    Confidence: rate-fallback
  • Repository review cost

    50K fresh input + 3K output tokens

    Mistral Medium 3.5 128B

    Mistral Medium 3.5 128B has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
  • Coding work

    Code generation, repair, and software-engineering tasks

    Not enough matched evidence

    Mistral Medium 3.5 128B is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like.

    Confidence: limited

Which one for a specific job

Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.

The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.

75.5GPT-6 Astra22.6Mistral Medium 3.5 128B

Directional only · BenchAlign v5.8

GPT-6 Astra has the higher coding point estimate. Conditional score ranges do not establish rank confidence.

Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.

Same basis rules as the category table below

What is actually comparable

Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.

1 category rests on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.

Shape of the matched evidence

Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.

A shared-evidence shape is not available.

BenchLM does not draw a radar or infer missing axes when the matched evidence is too sparse.

Category results, on a stated basis

Each row shows the public-lane category score for both models: the BenchAlign v5.8 lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.

Agentic

Like-for-like
GPT-6 Astra
74.8
Supported · #7/128
Mistral Medium 3.5 128B
19.8
Supported · #108/128
Basis
BenchAlign v5.8 lane · 14 vs 3 public rows
Reading
GPT-6 Astra leads

Knowledge

Like-for-like
GPT-6 Astra
86.2
Supported · #3/184
Mistral Medium 3.5 128B
31.8
Supported · #148/184
Basis
BenchAlign v5.8 lane · 7 vs 2 public rows
Reading
GPT-6 Astra leads

Coding

Directional only
GPT-6 Astra
75.5
Supported · #4/150
Mistral Medium 3.5 128B
22.6
Estimated · #114/150
Basis
BenchAlign v5.8 lane · 6 vs 2 public rows
Reading
Directional only

Reasoning

Not comparable
GPT-6 Astra
93.3
#1/28
Mistral Medium 3.5 128B
73.5
Unranked · 2 rankable rows
Basis
Provisional lane · 2 vs 0 weighted rows
Reading
Not comparable

Multimodal

Not comparable
GPT-6 Astra
87.3
Unranked · 3 rankable rows
Mistral Medium 3.5 128B
60.1
Unranked · 1 rankable row
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Multilingual

Not comparable
GPT-6 Astra
Not ranked
Mistral Medium 3.5 128B
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Instruction following

Not comparable
GPT-6 Astra
Not ranked
Mistral Medium 3.5 128B
84.0
#52/148
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Math

Not comparable
GPT-6 Astra
97.3
Unranked · 2 rankable rows
Mistral Medium 3.5 128B
Not ranked
Basis
Provisional lane · 2 vs 0 weighted rows
Reading
Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.8) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.

Supported evidence per lane · bars run 0–100Methodology

What each workload costs

Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.

Chat turn

1K fresh input + 500 output tokens

GPT-6 Astra
$0.035
Fits in one request
Mistral Medium 3.5 128B
$0.00525
Fits in one request

Mistral Medium 3.5 128B has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

GPT-6 Astra
$0.65
Fits in one request
Mistral Medium 3.5 128B
$0.0975
Fits in one request

Mistral Medium 3.5 128B has the lower modeled cost

Costs use the listed standard API rates.

Cache-heavy agent loop

200K cached + 20K fresh input + 10K output tokens

GPT-6 Astra
$0.9
Fits in one request
Mistral Medium 3.5 128B
$0.405
Fits in one request
Cached input priced at the published list-input rate

Mistral Medium 3.5 128B has the lower modeled cost

Mistral Medium 3.5 128B has no published cached-input rate, so cached tokens use its listed input rate.

Cached input falls back to the list input rate only where a cached rate is unpublished

Specification differences

Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.

Cached-input rate

A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.

GPT-6 Astra

$1 per 1M cached input tokens

OpenAI GPT-6 Astra model documentation

Mistral Medium 3.5 128B

Not published

Provider availability

GPT-6 Astra

Limited Availability · OpenAI Responses API, OpenAI Chat Completions API, ChatGPT Plus, Pro, Business, and Enterprise, Microsoft Azure, AWS Bedrock

OpenAI GPT-6 Astra model documentation

Mistral Medium 3.5 128B

Not sourced

Reasoning profile

GPT-6 Astra

Reasoning

Mistral Medium 3.5 128B

Reasoning

Weight access

GPT-6 Astra

Proprietary

Mistral Medium 3.5 128B

Open Weight

License

GPT-6 Astra

Proprietary

Mistral Medium 3.5 128B

Open Weight

Release date

GPT-6 Astra

2026-09-03

Mistral Medium 3.5 128B

2026-04-29

If you already use one of these models

Deployment change
The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
Quality signal
GPT-6 Astra has the higher public point estimate, 83.88 versus 33.62. Their conditional score ranges do not overlap. These ranges do not establish rank confidence.
Workload cost
Repository review: $0.65 vs $0.0975. Cache-heavy agent loop: $0.9 vs $0.405.
Context tradeoff
GPT-6 Astra has the larger documented window (1.05M).
Run the same representative tasks against both endpoints before changing production traffic.

Questions

Which is better, GPT-6 Astra or Mistral Medium 3.5 128B?

GPT-6 Astra has the higher public point estimate, 83.88 versus 33.62. Their conditional score ranges do not overlap. These ranges do not establish rank confidence. The page therefore keeps the decision tied to the specific documented workload.

Which is better for coding, GPT-6 Astra or Mistral Medium 3.5 128B?

GPT-6 Astra scores higher for coding on the public lane, 75.5 to 22.6. Mistral Medium 3.5 128B is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like. BenchLM does not name a winner for coding from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which is better for agentic tasks, GPT-6 Astra or Mistral Medium 3.5 128B?

GPT-6 Astra has the higher public agentic tasks point estimate, 74.8 to 19.8, with Supported evidence for both models. The conditional ranges do not establish rank confidence.

Which costs less, GPT-6 Astra or Mistral Medium 3.5 128B?

For the stated presets, chat costs $0.035 on GPT-6 Astra and $0.00525 on Mistral Medium 3.5 128B; repository review costs $0.65 and $0.0975; the cache-heavy agent loop costs $0.9 and $0.405. Mistral Medium 3.5 128B has no published cached-input rate, so cached tokens use its listed input rate.

Which has the larger context window, GPT-6 Astra or Mistral Medium 3.5 128B?

GPT-6 Astra has the larger documented context window: 1.05M, compared with 256K.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

GPT-6 Astra
API / mo$45,000
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Mistral Medium 3.5 128B
API / mo$6,750
Self-host / mo$6,990
Break-even71M/day
Model the full break-even

Benchmark evidence

The full public result ledger is available for audit without forcing a wide desktop table onto a phone.

Browse raw public benchmark evidence46 rows

Agentic

  • BrowseComp

    GPT-6 Astra91.5%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • OSWorld 2.0

    GPT-6 Astra72.6%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • Terminal-Bench 4.0

    GPT-6 Astra57.90%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • Terminal-Bench-Science 0.1

    GPT-6 Astra64.6%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • ExploitGym

    GPT-6 Astra42.4%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • Agents' Last Exam

    GPT-6 Astra59.3%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • AutomationBench

    GPT-6 Astra41.4%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • HLE w/ tools

    GPT-6 Astra57.2%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • Terminal-Bench 2.1 (Vals)

    GPT-6 Astra87.3%
    Source
    Mistral Medium 3.5 128B39.0%
    Source

    GPT-6 Astra leads this result

  • ApprenticeBench

    GPT-6 Astra68%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • CWE-bench v1

    GPT-6 Astra68.0%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • Hermes Index

    GPT-6 Astra56.3%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • Hermes Bench

    GPT-6 Astra73.7%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • MazeBench

    GPT-6 Astra23%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • τ³-bench results

    GPT-6 Astra—
    Mistral Medium 3.5 128B91.4%
    Source

    Not directly comparable

  • Gert Labs

    GPT-6 Astra—
    Mistral Medium 3.5 128B39.10%
    Source

    Not directly comparable

Coding

  • DeepSWE

    GPT-6 Astra74.1%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • FrontierCode 1.1 Main

    GPT-6 Astra53.3%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • FrontierCode 1.1 Extended

    GPT-6 Astra64.5%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • FrontierSWE v2

    GPT-6 Astra65.5%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • PostTrainBench v1.1

    GPT-6 Astra44.3%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • Bug Hunt Bench

    GPT-6 Astra45.0 fixes
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • SWE-bench Verified

    GPT-6 Astra—
    Mistral Medium 3.5 128B77.6%
    Source

    Not directly comparable

  • SWE-bench (Vals)

    GPT-6 Astra—
    Mistral Medium 3.5 128B66.4%
    Source

    Not directly comparable

Reasoning

  • STEMBench

    GPT-6 Astra2.81
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • ARC-AGI-1

    GPT-6 Astra98.50%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • ARC-AGI-2

    GPT-6 Astra95%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • ARC-AGI-3

    GPT-6 Astra62.7%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • GeneBench-Pro

    GPT-6 Astra37.8%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • MRCR v2 256K-512K

    GPT-6 Astra100.0%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • MRCR v2 512K-1M

    GPT-6 Astra96.3%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • GraphWalks BFS 256K–1M

    GPT-6 Astra71.8%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

Multimodal

  • ScreenSpot Pro

    GPT-6 Astra92.7%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • BenchCAD Vision2Code (tools)

    GPT-6 Astra0.959
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

Knowledge

  • GPQA

    GPT-6 Astra96%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • GPQA-D

    GPT-6 Astra96.0%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • HealthBench (raw)

    GPT-6 Astra56.9%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • HealthBench (length-adjusted)

    GPT-6 Astra58.3%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • HealthBench Professional

    GPT-6 Astra64.7%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • HealthBench Professional (raw)

    GPT-6 Astra68.2%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • HealthBench Hard

    GPT-6 Astra36.6%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • GPQA Diamond (Vals)

    GPT-6 Astra—
    Mistral Medium 3.5 128B34.8%
    Source

    Not directly comparable

  • MMLU-Pro (Vals)

    GPT-6 Astra—
    Mistral Medium 3.5 128B75.3%
    Source

    Not directly comparable

Instruction following

  • Gray Swan IPI (15 attempts)

    GPT-6 Astra8.5%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

Math

  • FrontierMath v2 (Tier 4)

    GPT-6 Astra97.600%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

  • FrontierMath v2 (Tiers 1-3)

    GPT-6 Astra93.684%
    Source
    Mistral Medium 3.5 128B—

    Not directly comparable

46 public results · 1 shared

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Last updated October 17, 2026