GPT-5.5 vs
GPT-5.6 Terra

Read the published evidence, route context, and missing facts before making a local decision. This page does not name a universal winner.

Models in this comparison

Provider identity and evidence state stay balanced across the pair.

O

OpenAI

GPT-5.5

Model type
Proprietary
Evidence state
Estimated evidence
Published context
1,000,000
VS
Model type
Proprietary
Evidence state
Estimated evidence
Published context
1,050,000

Key implications

Insufficient shared-metric coverage. Each finding is tied to a published metric, price, context, or modality fact.

  1. Input API price: GPT-5.6 Terra has the lower verified rate ($2.5 / 1M tokens vs $5 / 1M tokens).
  2. Output API price: GPT-5.6 Terra has the lower verified rate ($15 / 1M tokens vs $30 / 1M tokens).
  3. Context window: GPT-5.6 Terra has the larger published context window (1,050,000 tokens vs 1,000,000 tokens).

Shared metric view

A radar is shown only when at least four compatible supported score metrics are published.

Comparable metric detail

  • AgenticGPT-5.5: 64.71 · GPT-5.6 Terra: 58.86
  • CodingGPT-5.5: 72.5 · GPT-5.6 Terra: 69.29
  • KnowledgeGPT-5.5: 77.7 · GPT-5.6 Terra: 84.2
  • MathGPT-5.5: 71.1 · GPT-5.6 Terra: 97
  • MultimodalGroundedGPT-5.5: 65.3 · GPT-5.6 Terra: 71.4
  • ReasoningGPT-5.5: 79 · GPT-5.6 Terra: 78.1
  • OverallGPT-5.5: 72.92 · GPT-5.6 Terra: 72.95

Source metrics

Friendly metric names and published units stay visible. Missing measurements remain unavailable rather than becoming a score.

Source metric comparison
MetricUnitGPT-5.5GPT-5.6 Terra
Agenticscore64.7158.86
Codingscore72.569.29
Knowledgescore77.784.2
Mathscore71.197
MultimodalGroundedscore65.371.4
Reasoningscore7978.1
Overallscore72.9272.95

Agentic

Unit
score
GPT-5.5
64.71
GPT-5.6 Terra
58.86

Coding

Unit
score
GPT-5.5
72.5
GPT-5.6 Terra
69.29

Knowledge

Unit
score
GPT-5.5
77.7
GPT-5.6 Terra
84.2

Math

Unit
score
GPT-5.5
71.1
GPT-5.6 Terra
97

MultimodalGrounded

Unit
score
GPT-5.5
65.3
GPT-5.6 Terra
71.4

Reasoning

Unit
score
GPT-5.5
79
GPT-5.6 Terra
78.1

Overall

Unit
score
GPT-5.5
72.92
GPT-5.6 Terra
72.95

Pricing and context

Verification is shown beside each selected route. Missing facts remain Not verified.

Route pricing and context comparison
FieldUnitGPT-5.5GPT-5.6 Terra
Input API priceUSD / 1M tokens$5$2.5
Cached input API priceUSD / 1M tokens$0.5$0.25
Output API priceUSD / 1M tokens$30$15
Route contexttokens1,000,0001,050,000
Input modalitiespublished listNot verifiedNot verified
Output modalitiespublished listNot verifiedNot verified

Input API price

Unit
USD / 1M tokens
GPT-5.5
$5
GPT-5.6 Terra
$2.5

Cached input API price

Unit
USD / 1M tokens
GPT-5.5
$0.5
GPT-5.6 Terra
$0.25

Output API price

Unit
USD / 1M tokens
GPT-5.5
$30
GPT-5.6 Terra
$15

Route context

Unit
tokens
GPT-5.5
1,000,000
GPT-5.6 Terra
1,050,000

Input modalities

Unit
published list
GPT-5.5
Not verified
GPT-5.6 Terra
Not verified

Output modalities

Unit
published list
GPT-5.5
Not verified
GPT-5.6 Terra
Not verified

Evidence provenance

Source records, route identity, timestamps, and methodology are consolidated here without declaring either model a winner.

Publication time
Aug 30, 2026, 2:15 AM UTC
Freshness
Stale — Published weekly benchmark evidence has not refreshed within 8 days.
Methodology
benchlm: benchlm_raw_composite
Model records
  • GPT-5.5 — source benchlm · artifact models · model gpt-5-5
  • GPT-5.6 Terra — source benchlm · artifact models · model gpt-5-6-terra
Selected price routes
  • GPT-5.5 — route benchlm:gpt-5-5 · source benchlm · provider openai
  • GPT-5.6 Terra — route benchlm:gpt-5-6-terra · source benchlm · provider openai

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