Best AI for essay writing / head-to-head

Gemini 3.1 Pro Preview vs GPT-5.3-Codexfor essay writing

The verdict

GPT-5.3-Codex wins, 8883

Same 12 essay writing tasks, marked blind by three rival labs. GPT-5.3-Codex took 8 tasks, Gemini 3.1 Pro Preview took 2, 2 tied. Tested 13 Aug 2026.

Where they differed most

The task — Essay plan

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:** While critics argue that remote work diminishes collaborative innovation, evidence suggests it has not universally reduced productivity, but rather shifted it, enhancing individual output while requiring new management strategies to maintain team cohesion.

**1. Introduction: Defining Productivity in the Remote Era**
This section requires statistical evidence on the global shift to remote work post-2020 and academic definitions of productivity beyond mere hours worked.

**2. The Surge in Individual Output and Efficiency**
This secti…
**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.…

Task by task

TaskGemini 3.1 Pro PreviewGPT-5.3-Codex
Structured argument88
Essay plan105
Tighten flabby prose910
Hold a word count109
Adapt for the reader1010
Introduction only910
Steelman the other side89
Cite honestly45
Fix the structure510
Formal to plain910
Conclusion that adds something910
Refuse to pad910

Full receipts: Gemini 3.1 Pro Preview, GPT-5.3-Codex · judges claude-sonnet-5, gpt-5.6-terra, grok-4.5

Questions people ask

Which is better for essay writing: Gemini 3.1 Pro Preview or GPT-5.3-Codex?

GPT-5.3-Codex — it scored 88/100 against 83/100 on our 12-task essay writing suite, winning 8 tasks to 2 with 2 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.

More essay writing head-to-heads: GPT-5.3-Codex vs GPT-5.6 Sol · Gemini 3.1 Pro Preview vs GPT-5.6 Sol · GPT-5.3-Codex vs GPT-5.5 · Gemini 3.1 Pro Preview vs GPT-5.5 · GPT-5.3-Codex vs GPT-5.6 Luna · Gemini 3.1 Pro Preview vs GPT-5.6 Luna

Full ranking: Best AI for essay writing · model pages: Gemini 3.1 Pro Preview, GPT-5.3-Codex