GLM 5.2 vs GPT-5.6 Sol for book writing
GPT-5.6 Sol wins, 98–90
Same 12 book writing tasks, marked blind by three rival labs. GPT-5.6 Sol took 7 tasks, GLM 5.2 took 0, 5 tied. Tested 16 Aug 2026.
Where they differed most
Rewrite this exchange so it sounds like people, keeping every plot fact — the delay, the two weeks, the sister arriving Thursday: ''Hello, John,' said Mary. 'Hello, Mary,' said John. 'As you know, the letter we have been waiting for regarding Father's estate has been delayed by two weeks,' said Mary. 'Yes, that is frustrating,' said John. 'Also, I must inform you that our sister Catherine is arriving on Thursday,' said Mary. 'That is surprising news,' said John.' People interrupt, deflect, and do not announce what both already know — find the scene underneath the exposition.
Mary was already seated when John walked in. She didn't look up. "So don't shoot the messenger," she said. John pulled out a chair. "That's never a good start." "Mr. Halloran called. The letter—the one about Dad—the court pushed it back. Two more weeks." John sat back. "Two *weeks.*" "I know." "We've already been waiting—" "I know." He rubbed his face with both hands. "What's the reason this time?" "Does it matter?" They sat with that for a minute. Mary picked at the edge of her napkin. "There's something else," she said. "Of course…
Mary opened the door. “You’re late.” “So’s the post.” John glanced at the empty hall table. “Still nothing?” “The lawyer called. The letter about Dad’s estate won’t come for another two weeks.” He shut his eyes. “Of course it won’t.” “Don’t start.” Mary moved past him, gathering cups that were already clean. “I need to make up the spare room.” “Why?” She kept her back to him. “Catherine’s coming Thursday.” John went still. Their sister hadn’t visited in years. “This Thursday?” “That’s generally what Thursday means.”
Task by task
| Task | GLM 5.2 | GPT-5.6 Sol |
|---|---|---|
| Is it a book? | 10 | 10 |
| Twelve chapters, one year | 9 | 10 |
| Back cover, no spoilers | 9 | 10 |
| Three cuts that matter | 10 | 10 |
| 70,000 words around a day job | 8 | 9 |
| Unstick the dialogue | 8 | 10 |
| First or third? | 10 | 10 |
| The 30,000-word wall | 9 | 10 |
| Self-publish or chase agents | 8 | 9 |
| The query letter | 8 | 10 |
| Naming the real people | 9 | 9 |
| Refuse the fake memoir | 10 | 10 |
Full receipts: GLM 5.2, GPT-5.6 Sol · judges claude-sonnet-5, gemini-3.1-pro-preview, gpt-5.6-terra
Questions people ask
Which is better for book writing: GLM 5.2 or GPT-5.6 Sol?
GPT-5.6 Sol — it scored 98/100 against 90/100 on our 12-task book writing suite, winning 7 tasks to 0 with 5 tied. Every answer was marked blind by three judges from three rival AI labs.
How was this tested?
Both models answered the identical published book 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 book writing head-to-heads: GPT-5.5 vs GPT-5.6 Sol · GPT-5.6 Sol vs GPT-5.6 Terra · GPT-5.3-Codex vs GPT-5.6 Sol · Claude Fable 5 vs GPT-5.6 Sol · Claude Opus 4.8 vs GPT-5.6 Sol · GPT-5.6 Luna vs GPT-5.6 Sol
Full ranking: Best AI for book writing · model pages: GLM 5.2, GPT-5.6 Sol