Model
Model explorer

GPT-5.6 Terra

CLOSED
OpenAI · GPT-5.6 family · released Jul 9, 2026

Mid tier of the three-tier GPT-5.6 family (GA July 9, 2026 alongside Sol and Luna); OpenAI positions the tiers as 'durable capability tiers that can advance on their own cadence' — Terra is the balanced everyday model between flagship Sol and high-volume Luna. Same 1.05M context, 128K max output and Feb 2026 knowledge cutoff as Sol, at half Sol's price ($2.50/$15 vs $5/$30 per MTok). Distinct model tier, not a reasoning-effort configuration of Sol (each tier separately exposes its own effort settings).

ReasoningCodingVisionFunction callingTool useAgentic
2723.1
Elo · rank #7
Parameters
Undisclosed
Active params
—
Context
1.05M tokens
Architecture
Undisclosed architecture (presumed dense transformer); mid 'durable capability tier' of the GPT-5.6 Sol/Terra/Luna family, billed as balancing intelligence and cost
License
Proprietary
Languages
—
API price (in/out)
$2.5 / $15
Modalities
text · vision
Benchmark results
Bar shows position within the tracked field; marker = field best
Agents' Last ExamAgents50.4%#2
best: GPT-5.6 Sol · 52.7%
BrowseCompAgents87.5%#4
best: Kimi K3 · 91.2%
CyberGymCoding81.8%#3
best: GPT-5.6 Sol · 84.5%
FrontierBenchAgents20.8%#4
best: GPT-5.6 Sol · 34.4%
FrontierMath (Tiers 1-3)Math84.9%#2
best: GPT-5.6 Sol · 89.0%
FrontierMath (Tier 4)Math68.3%#2
best: GPT-5.6 Sol · 83.0%
GDPval-AAAgents1593#10
best: Claude Fable 5 · 1932
GPQA DiamondReasoning92.9%#11
best: GPT-5.6 Sol · 94.6%
Humanity's Last ExamReasoning41.8%#21
best: Claude Sonnet 5 · 57.4%
IFBenchReasoning71.2%#27
best: MiniMax M3 · 83.0%
MMMU-ProVision80.7%#9
best: Claude Opus 4.7 · 85.5%
SWE-bench ProCoding63.4%#6
best: Claude Fable 5 · 80.0%
τ³-BankingAgents31.8%#3
best: GPT-5.6 Sol · 33.0%
Terminal-Bench 2.0Coding87.4%#3
best: GPT-5.6 Sol · 88.8%
Run it locally
Closed weights — available via API only. No local deployment.
Input / M tok
$2.5
Output / M tok
$15
GPT-5.6 family
Elo progression across releases
GPT-5.6 LunaJul 20262679.5GPT-5.6 SolJul 20262948.0GPT-5.6 TerraJul 20262723.1
Resources
DOCSdevelopers.openai.com/api/docs/models/gpt-5.6-terraAPIAvailable via OpenAI API
API price $2.5/$15 · each benchmark row carries its own source badge (see methodology)