LLMcompare

Search

Search for a command to run...

A · closed · GPT-5.x

GPT-5.4 Nano

OpenAI

B · closed · GPT-5.x

GPT-5.5

OpenAI

0:12

overall capability wins (2 ties across 14 scored). GPT-5.5 leads overall.

  • Reasoning0:6
  • Coding0:3
  • Arena0:1
  • Tool use0:1
  • Composite indices0:2
  • Pricing3:0
  • Speed2:0
  • Specs0:1

Verdict

GPT-5.5 leads coding (widest gap: +23.6 on TermBench); GPT-5.5 ranks higher on LMArena (+74 Elo); GPT-5.5 offers ~2.6x larger context (1.1M vs 400K).

  • GPT-5.5 leads coding (widest gap: +23.6 on TermBench)
  • GPT-5.5 ranks higher on LMArena (+74 Elo)
  • GPT-5.5 offers ~2.6x larger context (1.1M vs 400K)
  • GPT-5.4 Nano is ~24.3x cheaper on a blended token basis than GPT-5.5

Cost for 1M in + 250K out

Illustrative chat workload at primary-provider list prices.

GPT-5.4 Nano
$0.51
GPT-5.5
$12.50

GPT-5.4 Nano is about 24.4x 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

Mar 17, 2026

Apr 23, 2026

Knowledge cutoff

-

-

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

$0.20

$5

A +$4.80

Output $/1M

$1.25

$30

A +$28.75

Blended $/1M (3∶1)

$0.46

$11.25

A +$10.79

Speed

tok/s

180

70

A +110

TTFT (s)

0.18

0.5

A +0.32

Reasoning

MMLU-Pro

—

—

—

GPQA Diamond

81.7

93.5

B +11.8 pts

Humanity's Last Exam

28.3

45.8

B +17.5 pts

AIME 2025

—

—

—

MATH-500

—

—

—

Humanity's Last Exam (with tools)

—

—

—

AA-Omniscience Accuracy

25.7

58.0

B +32.3 pts

AA-LCR v1.1

76.7

84.3

B +7.6 pts

CritPt

9.3

27.1

B +17.8 pts

MMMU-Pro

65.4

79.9

B +14.5 pts

IFBench

75.9

75.9

tie

Chartography

—

—

—

Chartography (With Tools)

—

—

—

Coding

SWE-bench Verified

—

—

—

SWE-bench Pro

52.4

58.6

B +6.2 pts

SWE-bench Multilingual

—

—

—

LiveCodeBench

—

—

—

Terminal-Bench 2.1

60.7

84.3

B +23.6 pts

Aider Polyglot

—

—

—

Terminal-Bench 3

—

—

—

BigCodeBench

—

—

—

SciCode

47.2

55.8

B +8.6 pts

CursorBench

—

58.4

—

SWE-Rebench

—

62.7

—

NL2Repo-Bench

—

—

—

DeepSWE

—

67.0

—

WebDev Arena

—

1,510

—

Terminal-Bench 4.0

—

—

—

CursorBench 4.0

—

—

—

FrontierCode v1.1 (Main)

—

—

—

Arena

LMArena Elo

1,402

1,476

B +74 Elo

GPT-5.4 Nano

Context
400K / 128K out
Parameters
—
Price
$0.20 / $1.25
Speed
180 tok/s · 0.18s TTFT
Modalities
text, image → text
License
Proprietary

Cheapest GPT-5.4 tier for high-volume classification and light assistants.

GPT-5.5

Context
1.1M / 128K out
Parameters
—
Price
$5 / $30
Speed
70 tok/s · 0.5s TTFT
Modalities
text, image → text
License
Proprietary

Prior OpenAI flagship with strong coding and long context; still widely used alongside the newer 5.6 family.

Benchmark charts

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

Reasoning & knowledge

GPQA: B +11.8HLE: B +17.5CritPt: B +17.8AA-LCR: B +7.6Omniscience Acc.: B +32.3MMMU-Pro: B +14.5IFBench: tie

Coding

SWE-Pro: B +6.2TermBench: B +23.6SciCode: B +8.6

Tool use & function calling

τ³-Banking: B +11.6

Arena

Arena Elo: B +74

Composite indices

AA Index: B +17.4AA Index v4.3: B +17.4

Pick a different pair · Back to catalog