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A · closed · GPT-5.x

GPT-5

OpenAI

B · closed · GPT-5.x

GPT-5.6 Sol

OpenAI

1:12

overall capability wins (1 ties across 14 scored). GPT-5.6 Sol leads overall.

  • Reasoning1:6
  • Coding0:3
  • Arena0:1
  • Tool use0:1
  • Pricing3:0
  • Speed1:1
  • Specs0:1

Verdict

GPT-5.6 Sol leads coding (widest gap: +52.8 on TermBench); GPT-5.6 Sol ranks higher on LMArena (+49 Elo); GPT-5.6 Sol offers ~2.6x larger context (1.1M vs 400K).

  • GPT-5.6 Sol leads coding (widest gap: +52.8 on TermBench)
  • GPT-5.6 Sol ranks higher on LMArena (+49 Elo)
  • GPT-5.6 Sol offers ~2.6x larger context (1.1M vs 400K)
  • GPT-5 is ~2.3x cheaper on a blended token basis than GPT-5.6 Sol

Cost for 1M in + 250K out

Illustrative chat workload at primary-provider list prices.

GPT-5
$3.75
GPT-5.6 Sol
$9

GPT-5 is about 2.4x cheaper on this workload.

Price per 1M tokens

Full comparison

Organization

OpenAI

OpenAI

Family

GPT-5.x

GPT-5.x

License

Proprietary

Proprietary

Open weights

No

No

Release

Aug 7, 2025

Jul 9, 2026

Knowledge cutoff

2024-09

2026-02-16

API / provider

OpenAI

OpenAI

Modalities

text, image → text

text, image → text

Specs

Context window

400K

1.1M

B +650K

Max output

128K

128K

tie

Parameters

—

—

—

Pricing

Input $/1M

$1.25

$4

A +$2.75

Output $/1M

$10

$20

A +$10

Blended $/1M (3∶1)

$3.44

$8

A +$4.56

Speed

tok/s

90

96

B +6.00

TTFT (s)

0.4

0.45

A +0.05

Reasoning

MMLU-Pro

—

—

—

GPQA Diamond

85.4

94.1

B +8.7 pts

Humanity's Last Exam

28.5

49.5

B +21.0 pts

AIME 2025

94.6

—

—

MATH-500

—

—

—

Humanity's Last Exam (with tools)

—

—

—

AA-Omniscience Accuracy

40.3

59.4

B +19.1 pts

AA-LCR v1.1

78.2

84.0

B +5.8 pts

CritPt

5.7

32.3

B +26.6 pts

MMMU-Pro

74.2

83.4

B +9.2 pts

IFBench

73.1

72.7

A +0.4 pts

Chartography

—

—

—

Chartography (With Tools)

—

—

—

Coding

SWE-bench Verified

74.9

—

—

SWE-bench Pro

41.8

64.6

B +22.8 pts

SWE-bench Multilingual

—

—

—

LiveCodeBench

—

—

—

Terminal-Bench 2.1

35.2

88.0

B +52.8 pts

Aider Polyglot

88.0

—

—

Terminal-Bench 3

—

34.6

—

BigCodeBench

—

—

—

SciCode

42.9

57.1

B +14.2 pts

CursorBench

—

67.2

—

SWE-Rebench

—

62.3

—

NL2Repo-Bench

—

—

—

DeepSWE

—

72.7

—

WebDev Arena

—

1,617

—

Terminal-Bench 4.0

—

37.3

—

CursorBench 4.0

—

—

—

FrontierCode v1.1 (Main)

—

—

—

Arena

LMArena Elo

1,435

1,484

B +49 Elo

GPT-5

Context
400K / 128K out
Parameters
—
Price
$1.25 / $10
Speed
90 tok/s · 0.4s TTFT
Modalities
text, image → text
License
Proprietary

Original GPT-5 GA release - still a strong price/performance option versus newer premium SKUs.

GPT-5.6 Sol

Context
1.1M / 128K out
Parameters
—
Price
$4 / $20
Speed
96 tok/s · 0.45s TTFT
Modalities
text, image → text
License
Proprietary

OpenAI's July 2026 flagship reasoning tier, tuned for hard STEM and agentic work; ChatGPT's top API SKU in the 5.6 family. Promotional Standard rates are $4/$20 (through at least Nov 21, 2026). Fast mode (2× price) delivers up to 2.5× Standard speed, and the Cerebras-powered Ultrafast preview reaches up to 750 tok/s.

Benchmark charts

Winner bars are emphasized. Per-benchmark deltas sit above each chart.

Reasoning & knowledge

GPQA: B +8.7HLE: B +21.0CritPt: B +26.6AA-LCR: B +5.8Omniscience Acc.: B +19.1MMMU-Pro: B +9.2IFBench: A +0.4

Coding

SWE-Pro: B +22.8TermBench: B +52.8SciCode: B +14.2

Tool use & function calling

τ³-Banking: B +22.2

Arena

Arena Elo: B +49

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