GPT-5.6 Luna vs GPT-5.6 Terra for workflow automation
Effectively a dead heat: 90–89
Same 12 workflow automation tasks, marked blind by three rival labs. GPT-5.6 Terra took 3 tasks, GPT-5.6 Luna took 1, 8 tied. Tested 27 Aug 2026.
Where they differed most
The nightly job that imports supplier price files has failed. What is true: it last succeeded 26 hours ago; the shop is still selling at yesterday's prices; three suppliers changed prices overnight; re-running the import by hand takes about 20 minutes; running it twice would double-apply a percentage uplift and corrupt the price list. Write ONLY the alert message that goes to the on-call person at 3am — max 60 words, nothing else, no heading, no explanation of your choices. It must say what has broken, what it is costing while it stays broken, the first action to take, and the one thing they must not do.
Supplier price import has failed; it last succeeded 26 hours ago, leaving the shop selling at yesterday’s prices while three suppliers’ overnight changes create ongoing margin loss. First, rerun the import manually (about 20 minutes). Do not run the import twice—this will double-apply the percentage uplift and corrupt the price list.
Nightly supplier price import failed. Store is selling yesterday’s prices while three suppliers changed overnight, risking margin loss or customer overcharging. First: check job status/logs for a partial run before retrying. Do not run the import twice—each duplicate run double-applies the percentage uplift and corrupts prices.
Task by task
| Task | GPT-5.6 Luna | GPT-5.6 Terra |
|---|---|---|
| The MOT reminder nobody sends | 9 | 9 |
| The spec, as JSON | 9 | 9 |
| Where the human stays | 9 | 9 |
| The unhappy paths are the job | 8 | 8 |
| Do not automate this | 9 | 10 |
| It fired twice | 9 | 10 |
| The spreadsheet that runs the business | 8 | 8 |
| The alert that wakes someone up | 10 | 8 |
| How long it really takes | 9 | 9 |
| No API, no chance? | 9 | 9 |
| Rules, not guesses | 8 | 9 |
| Refuse the scraper | 10 | 10 |
Full receipts: GPT-5.6 Luna, GPT-5.6 Terra · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5
Questions people ask
Which is better for workflow automation: GPT-5.6 Luna or GPT-5.6 Terra?
Effectively a dead heat: GPT-5.6 Terra edged it 90/100 to 89/100 on our workflow automation suite — too close to matter, so pick on price or the product you already use.
How was this tested?
Both models answered the identical published workflow automation tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.
More workflow automation head-to-heads: GPT-5.6 Sol vs GPT-5.6 Terra · GPT-5.6 Luna vs GPT-5.6 Sol · GPT-5.3-Codex vs GPT-5.6 Terra · GPT-5.3-Codex vs GPT-5.6 Luna · Claude Sonnet 5 vs GPT-5.6 Terra · GPT-5.5 vs GPT-5.6 Terra
Full ranking: Best AI for workflow automation · model pages: GPT-5.6 Luna, GPT-5.6 Terra