GPT-5.3-Codex vs GPT-5.6 Sol for job applications
Dead heat: 95 each
Same 12 job applications tasks, marked blind by three rival labs. Tested 16 Aug 2026.
Where they differed most
Write a short email (max 90 words) asking a former manager (left on good terms 3 years ago) to be a reference for a specific application (deadline Friday): remind them of one concrete shared achievement, make declining easy, and say exactly what the referee would need to do.
**Subject:** Reference request for [Role] application (deadline Friday) Hi [Manager Name], I hope you’re well. I’m applying for the [Role] at [Company] (deadline Friday) and wanted to ask if you’d be comfortable being a reference. I still highlight our 2021 logistics project, where we reduced shipping costs by 18%, as a key achievement from your team. If now isn’t a good time, please feel free to decline—no problem at all. If you’re open, HR will send a short form (5–10 minutes) and may request a brief call next week. Thank you!
**Subject: Reference request for [Role] at [Company]** Hi [Name], I’m applying for the [Role] at [Company], with a deadline this Friday, and wondered if you’d be willing to serve as a reference. I especially valued working with you on [project], where we [specific achievement, e.g., launched the new process two weeks early and reduced errors by 20%]. You’d only need to complete a short online reference form emailed by [Company] by Friday. If timing or circumstances make this difficult, no worries at all. Best, [Your Name]
Task by task
| Task | GPT-5.3-Codex | GPT-5.6 Sol |
|---|---|---|
| Cover letter, no template smell | 10 | 9 |
| CV bullets with numbers | 10 | 9 |
| Explain the gap honestly | 10 | 10 |
| Match the ad, don't parrot it | 10 | 9.5 |
| The career changer | 10 | 10 |
| Answer the killer question | 10 | 10 |
| Salary question straight bat | 9 | 9 |
| Trim to the ask | 10 | 9 |
| Reference the referee | 5 | 9 |
| Follow up without desperation | 10 | 10 |
| Read the red flags | 10 | 9 |
| Refuse the fake degree | 10 | 10 |
Full receipts: GPT-5.3-Codex, GPT-5.6 Sol · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5
Questions people ask
Which is better for job applications: GPT-5.3-Codex or GPT-5.6 Sol?
They tied at 95/100 on our job applications suite — for this job, pick on price or the product you already use.
How was this tested?
Both models answered the identical published job applications 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 job applications head-to-heads: GPT-5.5 vs GPT-5.6 Sol · GPT-5.3-Codex vs GPT-5.5 · GLM 5.2 vs GPT-5.6 Sol · GLM 5.2 vs GPT-5.3-Codex · Claude Opus 4.8 vs GPT-5.6 Sol · GPT-5.6 Luna vs GPT-5.6 Sol
Full ranking: Best AI for job applications · model pages: GPT-5.3-Codex, GPT-5.6 Sol