Best AI for essay writing / head-to-head
GPT-5.3-Codex vs GPT-5.5for essay writing
GPT-5.5 wins, 94–88
Same 12 essay writing tasks, marked blind by three rival labs. GPT-5.5 took 3 tasks, GPT-5.3-Codex took 2, 7 tied. Tested 13 Aug 2026.
Where they differed most
Produce a plan (not the essay) for a 2,000-word undergraduate essay on whether remote work has reduced productivity. Give a thesis in one sentence, five section headings, and one sentence per section saying what evidence it needs. Maximum 220 words total.
**Thesis (one sentence):** Remote work has not uniformly reduced productivity; its effects are heterogeneous across occupations, task types, and management practices, with average outcomes ranging from neutral to modestly positive when coordination systems are strong. 1. **Defining Productivity and Scope of the Question** Evidence needed: comparative definitions (output per hour, quality-adjusted output, innovation metrics) and boundary-setting data by sector (knowledge work vs. customer-facing/manual jobs) to avoid overgeneralization. 2.…
**Thesis:** Remote work has not uniformly reduced productivity; its effects depend on job type, management quality, collaboration needs, and how productivity is measured. 1. **Defining Productivity and Remote Work** Needs evidence on how productivity is measured in different sectors, including output, hours worked, efficiency, and employee performance metrics. 2. **Evidence That Remote Work Improves Productivity** Needs studies or surveys showing gains from fewer commutes, greater flexibility, improved focus, and higher employee satisfact…
Task by task
| Task | GPT-5.3-Codex | GPT-5.5 |
|---|---|---|
| Structured argument | 8 | 5 |
| Essay plan | 5 | 10 |
| Tighten flabby prose | 10 | 9 |
| Hold a word count | 9 | 9 |
| Adapt for the reader | 10 | 10 |
| Introduction only | 10 | 10 |
| Steelman the other side | 9 | 10 |
| Cite honestly | 5 | 10 |
| Fix the structure | 10 | 10 |
| Formal to plain | 10 | 10 |
| Conclusion that adds something | 10 | 10 |
| Refuse to pad | 10 | 10 |
Full receipts: GPT-5.3-Codex, GPT-5.5 · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5
Questions people ask
Which is better for essay writing: GPT-5.3-Codex or GPT-5.5?
GPT-5.5 — it scored 94/100 against 88/100 on our 12-task essay writing suite, winning 3 tasks to 2 with 7 tied. Every answer was marked blind by three judges from three rival AI labs.
How was this tested?
Both models answered the identical published essay writing 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.
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Full ranking: Best AI for essay writing · model pages: GPT-5.3-Codex, GPT-5.5