GPT-5.5 vs Grok 4.5 for workflow automation
Effectively a dead heat: 88–86
Same 12 workflow automation tasks, marked blind by three rival labs. GPT-5.5 took 5 tasks, Grok 4.5 took 2, 5 tied. Tested 18 Aug 2026.
Where they differed most
The process, as the office manager of a small Bristol removals firm describes it: 'A quote request comes in on the website form. Someone reads it, decides if it is within our area, and if it is we email a price from the ready reckoner. If it is a big job we go and look at it first. If they accept we take a 20% deposit and put it in the calendar, and if the deposit does not arrive within a week the slot goes back.' Reply with ONLY valid JSON — no prose before or after. An object with exactly these keys and no others: trigger (string), steps (an array of objects, each with keys step (number), action (string), automated (boolean), on_error (string)), human_decisions (an array of objects with keys decision (string) and why_human (string)), and open_questions (an array of strings — the things the description does not tell you and that must be answered before this could be built).
{
"trigger": "A quote request is submitted via the website form.",
"steps": [
{
"step": 1,
"action": "Receive the quote request from the website form.",
"automated": true,
"on_error": "If the form submission is incomplete or fails, notify the office team and ask the customer to resubmit or provide missing details."
},
{
"step": 2,
"action": "Review the request details.",
"automated": false,
"on_error": "If the request cannot be understood, contact the customer for clarification."…{
"trigger": "Quote request submitted via website form",
"steps": [
{
"step": 1,
"action": "Read incoming quote request from website form",
"automated": false,
"on_error": "Flag for manual review or request missing details from customer"
},
{
"step": 2,
"action": "Decide if job is within service area",
"automated": false,
"on_error": "Reject or refer out-of-area request and notify customer"
},
{
"step": 3,
"action": "Assess if job is large enough to require site…Task by task
| Task | GPT-5.5 | Grok 4.5 |
|---|---|---|
| The MOT reminder nobody sends | 8 | 8 |
| The spec, as JSON | 9 | 8 |
| Where the human stays | 9 | 8 |
| The unhappy paths are the job | 8 | 8 |
| Do not automate this | 9 | 10 |
| It fired twice | 9 | 8 |
| The spreadsheet that runs the business | 9 | 9 |
| The alert that wakes someone up | 10 | 9 |
| How long it really takes | 8 | 9 |
| No API, no chance? | 9 | 9 |
| Rules, not guesses | 9 | 8 |
| Refuse the scraper | 9 | 9 |
Full receipts: GPT-5.5, Grok 4.5 · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5
Questions people ask
Which is better for workflow automation: GPT-5.5 or Grok 4.5?
Effectively a dead heat: GPT-5.5 edged it 88/100 to 86/100 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-5.5 vs GPT-5.6 Sol · GPT-5.6 Sol vs Grok 4.5 · Claude Sonnet 5 vs GPT-5.5 · Claude Sonnet 5 vs Grok 4.5 · GPT-5.5 vs Kimi K3 · Claude Opus 4.8 vs GPT-5.5
Full ranking: Best AI for workflow automation · model pages: GPT-5.5, Grok 4.5