BenchLeader

Gemini 4 Argon vs GPT-5-Codex

Full profiles: Gemini 4 Argon (Google) and GPT-5-Codex (OpenAI): every benchmark, price and rank.

Updated · Data from 8 sources

As of 29 Oct 2026, Gemini 4 Argon is ahead of GPT-5-Codex on quality (65.9 vs 58.6 on the BenchLeader Index), but GPT-5-Codex is 2.3× cheaper at $3.44 vs $8.00 per 1M tokens blended. Choose Gemini 4 Argon for coding (67 vs 59) and long context (65 vs 61); choose GPT-5-Codex for fast first answers (10.9 s vs 47.3 s) and agents & tools (67 vs 59), where it also streams ~2× faster. Gemini 4 Argon's current price runs until 30 Nov 2026, then $8.00.

Key facts (as of 29 Oct 2026)

  • Gemini 4 Argon scores 65.9 on the BenchLeader Index and GPT-5-Codex scores 58.6 (BenchLeader, 29 Oct 2026).
  • Gemini 4 Argon costs $8.00 per 1M tokens blended until 30 Nov 2026, then $8.00 (https://ai.google.dev/gemini-api/docs/pricing, checked 20 Oct 2026).
  • GPT-5-Codex costs $3.44 per 1M tokens blended (list price, 29 Oct 2026).
  • GPT-5-Codex streams ~2× faster than Gemini 4 Argon (Artificial Analysis, 7-day median, 29 Oct 2026).
  • Of the 4 benchmarks both models have, Gemini 4 Argon leads 4 (BenchLeader, 29 Oct 2026).

Which to pick for…

The pick's numbers come first. Category scores on the BenchLeader scale (50 is the average model, 15 points one standard deviation). High confidence means a lead of half a standard deviation or more; under one point is called either.

Use casePickWhyConfidence
CodingGemini 4 Argon67 vs 59 category scoreHigh
Agents & tool useGPT-5-Codex67 vs 59 category scoreHigh
Long documentsGemini 4 Argon65 vs 61 category score; AA-LCR v1.1 79.7% vs 71.7%Medium
Chat quality (human preference)–Only Gemini 4 Argon has an Arena rating (72 category score)Not comparable
Lowest costGPT-5-Codex$3.44 vs $8.00 per 1M blended; agentic coding session $0.115 vs $0.320; from 1 Dec 2026: $3.44 vs $8.00–
Fastest first answerGPT-5-Codex10.9 s (GPT-5-Codex (high)) vs 47.3 s (Gemini 4 Argon (high)) to the first answer token–
High volume on a budgetNeither flagshipA smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs–

Key differences

  • Gemini 4 Argon (high) leads on quality: 65.9 vs 58.6.
  • Gemini 4 Argon (high) is stronger in coding, human preference, knowledge, long context, maths, reasoning.
  • GPT-5-Codex (high) is stronger in agents & tools, instruction following, multimodal.
  • GPT-5-Codex (high) is 2.3× cheaper ($3.44 vs $8.00 per 1M blended) until 30 Nov 2026, then $3.44 vs $8.00 from 1 Dec 2026.
  • GPT-5-Codex (high) streams 2.4× faster (195 vs 83 tokens per second).

At a glance

SpecGemini 4 ArgonGPT-5-Codex
DeveloperGoogleOpenAI
Released30 Sept 202615 Sept 2025
Generally available13 Oct 202615 Sept 2025
Context window (tokens)1,048,576400,000
Max output (tokens)65,536 (up to 1,048,576 with long decode)–
Input typestext, image, video, audio, PDF–
Reasoning effort settingslow, medium, high–
Compared atGemini 4 Argon (high)GPT-5-Codex (high)
Open weightsNoNo
Price in / out / cached input per 1M$4.00 / $20.00 / $0.100$1.25 / $10.00 / $0.125
Announced price change$4.00 / $20.00 / $0.200 from 1 Dec 2026None announced
API model IDgemini-4-argon–
Where to use itGemini API (AI Studio), Gemini Enterprise Agent Platform, Gemini app–

Limits, availability and announced prices from the vendors' own pages: ai.google.dev, ai.google.dev pricing (checked 20 Oct 2026). Everything else is from the day's data.

Category by category

Category scores on the BenchLeader scale: 50 is the average evaluated model, 15 points is one standard deviation. A gap under one point is called level.

CategoryGemini 4 Argon (high)GPT-5-Codex (high)Leader
Reasoning71.2–not comparable
Coding66.558.5Gemini 4 Argon
Agents & tools58.866.8GPT-5-Codex
Maths70.3–not comparable
Knowledge73.1–not comparable
Instruction following–72.4not comparable
Human preference71.6–not comparable
Multimodal–56.4not comparable
Long context64.760.5Gemini 4 Argon

Where sources disagree

Across the 4 benchmarks both have, Gemini 4 Argon leads 4, GPT-5-Codex leads 0. Every overall index that rates both puts Gemini 4 Argon ahead.

Overall indexGemini 4 Argon (high)GPT-5-Codex (high)Leader
BenchLeader Index65.958.6Gemini 4 Argon

Each publisher runs its own tasks, harnesses and effort settings, so their overall verdicts can differ; BenchLeader reconciles them on one scale. † measured at another effort setting of the same model (the publisher did not test the one compared here).

Price, speed and latency

List prices blended at three input tokens per output token. Per-task prices use the token counts on the methodology page; suite cost is what Artificial Analysis paid to run its whole Intelligence Index.

MeasureGemini 4 Argon (high)GPT-5-Codex (high)
Blended price per 1M tokens, until 30 Nov 2026$8.00$3.44
Input / output per 1M$4.00 / $20.00$1.25 / $10.00
Blended price per 1M from 1 Dec 2026$8.00$3.44
Input / output per 1M from 1 Dec 2026$4.00 / $20.00$1.25 / $10.00
Cached input per 1M$0.100$0.125
Price per task: chat reply$0.0076$0.0035
Price per task: summarize a 30-page report$0.060$0.021
Price per task: code edit$0.054$0.022
Price per task: agentic coding session$0.320$0.115
Price per task: structured extraction$0.012$0.0045
Cost to run a full benchmark suite$7.68–
Output speed83 tok/s195 tok/s
Time to first answer47.3 s10.9 s
Time to a complete answer53.3 s13.4 s

Each model is compared at its best-ranked reasoning-effort setting. Gemini 4 Argon (high) scores 65.9 and takes 47 s to its first answer token; Gemini 4 Argon scores 63.1 in 5 s. GPT-5-Codex (high) scores 58.6 and takes 11 s to its first answer token. Higher effort means more thinking before the answer: better scores, longer waits and more tokens billed. How reasoning effort changes scores and cost.

Every benchmark

125 benchmarks, grouped by category; each name links to the board and its leaders. † measured at another effort setting of the same model, shown for reference and not counted as a win.

MetricPublisherGemini 4 Argon (high)GPT-5-Codex (high)
BenchLeader IndexBenchLeader65.958.6
Agents & tools scoreBenchLeader58.866.8
Coding scoreBenchLeader66.558.5
Human preference scoreBenchLeader71.6–
Knowledge scoreBenchLeader73.1–
Long context scoreBenchLeader64.760.5
Maths scoreBenchLeader70.3–
Reasoning scoreBenchLeader71.2–
Instruction following scoreBenchLeader–72.4
Multimodal scoreBenchLeader–56.4
Blended price $/MBenchLeader$8.00$3.44
Output speedBenchLeader83 tok/s195 tok/s
Time to first answerBenchLeader47.3 s10.9 s
Context windowBenchLeader1,048,576 tokens400,000 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub96.4%–
Arena Hard PromptsArena (LMArena)1540–
LiveBench 2.0 ReasoningLiveBench95.1%†–
GPQA Diamond (AA)Artificial Analysis–83.7%
Humanity's Last Exam (AA)Artificial Analysis57.1%27.9%
HLE-Diamond (AA)Artificial Analysis56.7%–
Kagi LLM BenchmarkKagi LLM Benchmark–70.3%†
ARC-AGI-1ARC Prize98.5%–
ARC-AGI-2ARC Prize91.3%–
ARC-AGI-3ARC Prize97.3%–
CritPtArtificial Analysis27.1%5.1%
CritPt v2 hard subset (AA)Artificial Analysis52.5%–
MysteryMechanismVals AI45.5%–
Chess PuzzlesEpoch AI Benchmarking Hub59.0%–
Mystery Game PuzzlesEpoch AI Benchmarking Hub64.0%–
LMCAEpoch AI Benchmarking Hub63.7%–
DTBenchEpoch AI Benchmarking Hub97.3%–
Coding
SciCodeSciCode61.8%–
WeirdMLWeirdML–54.5%
FrontierCodeCognition47.5%†–
Arena CodingArena (LMArena)1552–
Arena WebDevArena (LMArena)1680–
LiveBench 2.0 CodingLiveBench89.7%†–
LiveCodeBenchVals AI–84.7%
IOIVals AI100.0%–
Show all 125 benchmarks
MetricPublisherGemini 4 Argon (high)GPT-5-Codex (high)
Coding
Code MigrationVals AI68.2%–
Code Migration v1.1Vals AI70.8%–
ProgramBenchVals AI2.5%–
SWE-bench MultimodalVals AI56.0%–
Vibe Code Bench 1-100Vals AI21.2%–
Vibe Code Bench v1.1Vals AI91.9%–
MirrorCodeEpoch AI Benchmarking Hub58.9%–
CursorBenchCursor52.9%–
ALE-BenchEpoch AI Benchmarking Hub2100.1–
FrontierSWEEpoch AI Benchmarking Hub55.0%–
Terminal-Bench 4.0 (AA)Artificial Analysis57.1%–
Startrise FrontendStartrise71.0%†–
FrontierCode 1.1 (AA)Artificial Analysis43.5%–
FrontierCode 2.0 (AA)Artificial Analysis25.7%–
LiveCodeBench (AA)Artificial Analysis–84.0%
Agents & tools
Terminal-BenchTerminal-Bench–44.3%†
Remote Labor IndexScale AI / CAIS17.1%†–
APEX-AgentsMercor82.4%†–
Arena AgentArena (LMArena)11.7–
LiveBench Long AgenticLiveBench61.2%†–
LiveBench BrowserLiveBench82.8%†–
Terminal-Bench HardArtificial Analysis–37.9%
τ²-Bench Telecom (AA)Artificial Analysis–86.8%
Terminal-Bench 2.1 (Vals)Vals AI57.7%–
HiL-BenchScale AI SEAL62.0%†–
GDPval-AA v2.1, normalised scoreArtificial Analysis56.2%–
GDPval-AA v2.1Artificial Analysis1631–
Analyst Agent (AA)Artificial Analysis48.8%–
CUA-benchVals AI4.8%–
CyberBenchVals AI77.9%–
Finance Agent v2Vals AI65.4%–
Finance Agent v2.1Vals AI67.7%–
Harvey's Legal Agent Benchmark v1.1Vals AI27.1%–
Harvey's Legal Agent Benchmark v1Vals AI19.6%–
Legal Research BenchVals AI54.8%–
Robo-benchVals AI0.8%–
SREBenchVals AI44.3%–
Tax Agent BenchVals AI44.6%–
Terminal-Bench 4.0 (Vals)Vals AI57.6%–
Terminal-Bench ScienceVals AI44.3%–
Time Horizon Index: KSPVals AI52.5%–
Vending-Bench 2Andon Labs13718.2†–
AutomationBenchArtificial Analysis77.5%–
GDP.pdf (AA)Artificial Analysis21.8%–
Harvey LAB-AA v1.1Harvey3.9%–
AA-Briefcase v1.1Artificial Analysis1483–
Terminal-Bench-Science 0.1 (AA)Artificial Analysis52.9%–
FACTS SearchGoogle84.0%†–
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub86.0%–
FrontierMath Tier 4Epoch AI Benchmarking Hub78.0%–
OTIS Mock AIMEEpoch AI Benchmarking Hub100.0%–
ProofBenchVals AI99.0%†–
Arena MathsArena (LMArena)1532–
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub76.0%–
LiveBench 2.0 Data AnalysisLiveBench85.2%†–
LiveBench ResearchLiveBench83.1%†–
AA-Omniscience v1.1Artificial Analysis46.1–
LegalBenchVals AI88.3%–
PRBench FinanceScale AI SEAL49.9%†–
PRBench LegalScale AI SEAL49.4%†–
BioMysteryBenchVals AI76.3%–
Excel Modeling BenchmarkVals AI75.2%–
Excel Modeling Benchmark v1.1Vals AI74.8%–
MedCodeVals AI58.8%–
MedScribeVals AI87.4%–
Public Benefits Bench v1.1Vals AI69.8%–
DrugDiscoveryBenchScale AI SEAL65.4%–
EBR-benchEpoch AI Benchmarking Hub64.8%–
GDP.pdfEpoch AI Benchmarking Hub28.4%–
AA-Omniscience v1.1: accuracyArtificial Analysis48.3%–
AA-Omniscience v1.1: non-hallucinationArtificial Analysis95.7%–
HealthBench Professional (AA)OpenAI55.0%–
Instruction following
IFBenchArtificial Analysis–74.2%
MultiChallengeScale AI SEAL78.7%†–
Arena Instruction FollowingArena (LMArena)1519–
Human preference
Arena TextArena (LMArena)1517–
EQ-Bench 4EQ-Bench1236†–
Arena Creative WritingArena (LMArena)1512–
Arena Multi-turnArena (LMArena)1544–
Arena Longer QueriesArena (LMArena)1535–
Multimodal
LiveBench DesignLiveBench73.7%†–
MMMU-ProArtificial Analysis–73.8%
SAGEVals AI89.5%–
AudioMCScale AI SEAL58.4%–
AudioMC (text output)Scale AI SEAL58.4%–
Blueprint-Bench 2Epoch AI Benchmarking Hub54.5%†–
Code2Video-AAArtificial Analysis1259–
AA-3DArtificial Analysis1153–
Long context
AA-LCR v1.1Artificial Analysis79.7%71.7%
MLCRArtificial Analysis13.9%–
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub166.4†–
LiveBench 2.0LiveBench79.3%†–
AA Intelligence Index v5.0Artificial Analysis50.4–
AA Intelligence Index v4.3.2Artificial Analysis52.624.9
AA Progress Index v1Artificial Analysis341.8275.1
Vals IndexVals AI69.2–
Vals Finance IndexVals AI64.9%–
Vals RSI IndexVals AI30.6%–
Vals Science IndexVals AI55.4%–
Vals Router IndexVals AI69.2%†–

Data as of 2026-10-29. Best configuration of each model; every score links to its source on the model pages.

What changed

  • Gemini 4 Argon: list price moves to $4.00 / $20.00 per 1M input / output tokens (announced).
  • Gemini 4 Argon (high): input price moved from $2.00/M to $4.00/M (100% up); output price moved from $10.00/M to $20.00/M (100% up); cost per task moved from $3.84/M to $7.68/M (100% up).
  • Gemini 4 Argon (high): BenchLeader Index 66.8 → 65.9.
  • Gemini 4 Argon (high): 5 new results (AA Intelligence Index v5.0, AA Progress Index v1, HLE-Diamond (AA)…); 5 score revisions; cost per task moved from $1.62/M to $3.84/M (137% up).
  • GPT-5-Codex (high): 1 new result (AA Progress Index v1).
  • Gemini 4 Argon (high): BenchLeader Index 68.5 → 66.8.
  • Gemini 4 Argon (high): 1 new result (Terminal-Bench 2.1 (Vals)).
  • Gemini 4 Argon (high): cost per task moved from $1.99/M to $1.62/M (19% down).
  • Gemini 4 Argon (high): 10 new results (Code Migration v1.1, Excel Modeling Benchmark v1.1, Finance Agent v2.1…); 7 score revisions.
  • Gemini 4 Argon (high): BenchLeader Index 69.0 → 68.5.

Rankings: Best LLM overall · Best LLM for agents · Best cheap LLMs

Gemini 4 Argon vs GPT-5-Codex: questions

Is Gemini 4 Argon better than GPT-5-Codex?
Gemini 4 Argon (high) leads on quality: 65.9 vs 58.6. The BenchLeader Index combines every independent quality benchmark; Gemini 4 Argon (high) is ahead overall as of 29 Oct 2026, but check the category scores for your use.
Gemini 4 Argon vs GPT-5-Codex: which is cheaper, and will that change?
GPT-5-Codex is cheaper today: $3.44 against $8.00 per million tokens, blended at three input tokens per output token. Gemini 4 Argon's current price runs until 30 Nov 2026, then $8.00.
Is Gemini 4 Argon or GPT-5-Codex better for coding?
Gemini 4 Argon scores higher in coding (67 vs 59 on the category index, where 50 is average).
Which is faster, Gemini 4 Argon or GPT-5-Codex?
GPT-5-Codex streams ~2× faster (195 vs 83 output tokens per second, Artificial Analysis 7-day median).
Is Gemini 4 Argon or GPT-5-Codex better for agents and tool use?
GPT-5-Codex scores higher in agentic tasks (67 vs 59 on the category index, where 50 is average).
More questions (4)
Which is better for long documents?
Gemini 4 Argon scores higher on long-context benchmarks (65 vs 61). Gemini 4 Argon accepts more context: 1,048,576 against 400,000 tokens for GPT-5-Codex.
Which has lower latency?
GPT-5-Codex answers first: 10.9 s against 47.3 s to the first answer token, as Artificial Analysis measures it. Reasoning effort drives most of this: a higher setting thinks longer before it answers.
Do independent benchmarks agree on Gemini 4 Argon vs GPT-5-Codex?
Across the 4 benchmarks both have, Gemini 4 Argon leads 4, GPT-5-Codex leads 0. Every overall index that rates both puts Gemini 4 Argon ahead.
When was Gemini 4 Argon released?
Gemini 4 Argon became generally available on 13 Oct 2026, after first appearing on 30 Sept 2026.