GPT-5.6 Luna vs GPT-5.6 Sol for workflow automation
GPT-5.6 Sol wins, 92–89
Same 12 workflow automation tasks, marked blind by three rival labs. GPT-5.6 Sol took 3 tasks, GPT-5.6 Luna took 0, 9 tied. Tested 27 Aug 2026.
Where they differed most
An online florist's order process: order placed, payment taken, delivery slot allocated, courier label printed, confirmation email sent. The happy path is five minutes' work. Here are five things that actually happen. For each, write one line — exactly 5 bullets, in the order given, one line each, no sub-points — saying what the automation does, whether it retries, and whether it escalates to a person or resolves itself: 1) the card payment is declined after the order row has already been written; 2) the confirmation email hard-bounces; 3) the stem the customer ordered is out of stock at the time of picking, not at the time of ordering; 4) the courier's API returns a 500 while printing the label; 5) the customer replies to the no-reply confirmation address with 'please change the delivery date'.
- **Payment declined:** Mark the order unpaid and pause or cancel fulfillment, do not retry a definitive decline, and notify the customer to provide another payment method without escalating to a person. - **Confirmation email hard-bounces:** Record the address as undeliverable, do not retry, and create a support task for a person to contact the customer another way. - **Stem out of stock at picking:** Pause fulfillment, automatically check approved substitutions or offer a refund, and escalate to the customer or a person if no pre-authorized r…
- Marks the order payment-failed, releases reserved stock and slot, does not retry the card, and automatically cancels unless the customer supplies new payment. - Suppresses the invalid email address, sends the confirmation by SMS, does not retry the hard bounce, and resolves automatically. - Pauses fulfilment, does not retry picking the unavailable stem, and escalates to a florist or support agent for substitution or refund. - Retries the label request idempotently with backoff, resolves automatically if successful, and escalates to a person a…
Task by task
| Task | GPT-5.6 Luna | GPT-5.6 Sol |
|---|---|---|
| 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 | 9 |
| Do not automate this | 9 | 9 |
| It fired twice | 9 | 9 |
| The spreadsheet that runs the business | 8 | 9 |
| The alert that wakes someone up | 10 | 10 |
| How long it really takes | 9 | 9 |
| No API, no chance? | 9 | 10 |
| Rules, not guesses | 8 | 8 |
| Refuse the scraper | 10 | 10 |
Full receipts: GPT-5.6 Luna, GPT-5.6 Sol · 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 Sol?
GPT-5.6 Sol — it scored 92/100 against 89/100 on our 12-task workflow automation suite, winning 3 tasks to 0 with 9 tied. Every answer was marked blind by three judges from three rival AI labs.
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-5.3-Codex vs GPT-5.6 Sol · GPT-5.6 Sol vs GPT-5.6 Terra · Claude Sonnet 5 vs GPT-5.6 Sol · GPT-5.5 vs GPT-5.6 Sol · GPT-5.6 Sol vs Grok 4.5 · GPT-5.6 Sol vs Kimi K3
Full ranking: Best AI for workflow automation · model pages: GPT-5.6 Luna, GPT-5.6 Sol