GPT-5.6 Terra
openai/gpt-5.6-terra
balances intelligence and cost.
cmd --model gpt-5.6-terra
Intelligence index
56.6
Output speed
120.5 tok/s
Input
$2 /M
Output
$12 /M
Cache read
$0.20 /M
Agent-loop cost
$0.74 /M in
Context window
1.05M tokens
Released
July 9, 2026
Modalities
→
vs. the lineup
GPT-5.6 Terra beside its stablemates and nearest rivals. The ◆ marks the best value in each column across every row shown.
pin a rival:
| Model | Intelligence | Coding | Speed | Input $/M | Output $/M | Blended $/M | Context |
|---|---|---|---|---|---|---|---|
| GPT-5.6 Sol | 60.9◆ | 77.4◆ | 64.7◆ | $5◆ | $30◆ | $11.25◆ | 1.05M◆ |
| GPT-5.6 Terra ◆ | 56.6◆ | 76.7◆ | 120.5◆ | $2◆ | $12◆ | $4.50◆ | 1.05M◆ |
| GPT-5.5 | 56.3◆ | 74.9◆ | —◆ | $5◆ | $30◆ | $11.25◆ | 200K◆ |
| GPT-5.4 | 53.1◆ | 71.1◆ | —◆ | $2.50◆ | $15◆ | $5.63◆ | 400K◆ |
| GPT-5.6 Luna | 52.3◆ | 71.4◆ | 159.5◆ | $0.20◆ | $1.20◆ | $0.45◆ | 1.05M◆ |
| GPT-5.3 Codex | 45.5◆ | —◆ | 118.6◆ | $2◆ | $8◆ | $3.50◆ | 400K◆ |
| DeepSeek V4 Pro (latest)pinned | 45.3◆ | 59.4◆ | 63.3◆ | $0.43◆ | $0.87◆ | $0.54◆ | 1M◆ |
| DeepSeek V4 Flash (latest)pinned | 52◆ | 69.1◆ | 115.9◆ | $0.14◆ | $0.28◆ | $0.18◆ | 1M◆ |
coding performance
The Intelligence Index and its sub-scores, ranked against every scored model in the catalog. A metric that has not been measured for GPT-5.6 Terra has been left empty.
Coding Index
76.7
#3 of 40 scored
Terminal-Bench
88
#3 of 40 scored
Intelligence Index
56.6
#8 of 46 scored
Long-context reasoning
79.7
reasoning across a long context
SciCode
53.9
scientific coding
GPQA Diamond
92.5
graduate-level QA
price bands
GPT-5.6 Terra is not billed at one flat rate — the price changes with how much context a request carries. The header quotes the standard band; here is every band.
| Band | Context | Input $/M | Output $/M | Cache read $/M |
|---|---|---|---|---|
| Standard | ≤ 272K | $2.00 | $12.00 | $0.20 |
| Long context | > 272K | $4.00 | $18.00 | $0.40 |
usage calculator
How far a month of credits goes on GPT-5.6 Terra.
GPT-5.6 Terra runs on Pro and up — from $20/mo.
Input tokensfresh prompt
800Output tokensmodel reply
180Cache read tokensre-read context
50Kcost / request $0.014 · in $2 · out $12 · cache $0.20 per M
fresh input 12%output 16%cache reads 73%
Requests / 30 days
1.5K
$20 credits ÷ $0.014 per request
~291 quick fixes~58 bug fixes~10 feature PRs
what real work costs
Real coding tasks priced end to end on GPT-5.6 Terra, from a quick lookup to a full-repo agent run.
One agent task
$0.26
180K in at 75% cache hit, 12K out
What you pay
$1.36 /M
all-in across every token that task touched
Sticker input
$2 /M
cache reads bill at $0.20 /M instead
| Task | Tokens in · out | GPT-5.6 Terra | Muse Spark 1.2 | Claude Haiku 4.5 |
|---|---|---|---|---|
| Quick lookup / one-liner | 8K · 1K | $0.02 | $0.0063 | $0.0065 |
| Review a 500-line PR | 60K · 4K | $0.09 | $0.05 | $0.04 |
| Fix a bug (agent loop) | 180K · 12K | $0.26 | $0.13 | $0.12 |
| Refactor a module | 320K · 20K | $0.47 | $0.23 | $0.21 |
| Full-repo agent run | 900K · 45K | $1.08 | $0.54 | $0.49 |
frequently asked
What is GPT-5.6 Terra best for?+
GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic tasks where capability and cost need to be balanced, offering strong performance at roughly half the cost of Sol.
How much does GPT-5.6 Terra cost?+
$2/M input and $12/M output, cache reads $0.20/M. In an agent loop most input is cache-read, so the effective input rate is about $0.74/M.Which plan do I need?+
Available on Pro and above.
How do I switch to it?+
Run
cmd --model gpt-5.6-terra, or type /model in a session and pick it. You can switch mid-session without losing context.Ship code that matches your taste
Command Code is the AI coding agent that continuously learns your taste. Start for $1.
Benchmarks from Artificial Analysis (v4.1)commandcode.ai/models/gpt-5-6-terra