GPT-5.3-Codex vs GPT-5.6 Sol for translation
GPT-5.6 Sol wins, 96–93
Same 12 translation tasks, marked blind by three rival labs. GPT-5.6 Sol took 4 tasks, GPT-5.3-Codex took 1, 7 tied. Tested 16 Aug 2026.
Where they differed most
Translate into French for a couple in their 60s the writer has never met — vous throughout, natural French correspondence rather than word-for-word: 'Dear Monsieur and Madame Perrin, Thank you so much for having us in September. We will arrive in Limoges by train on Friday the 12th at around 6pm. My husband is allergic to shellfish, but otherwise we eat everything. Could we bring you anything from England that you miss? With best wishes, Janet.'
Monsieur et Madame Perrin, Merci beaucoup de nous accueillir en septembre. Nous arriverons à Limoges en train le vendredi 12, vers 18 h. Mon mari est allergique aux fruits de mer, mais à part cela, nous mangeons de tout. Souhaitez-vous que nous vous apportions quelque chose d’Angleterre qui vous manque ? Bien cordialement, Janet
Monsieur et Madame Perrin, Merci beaucoup de bien vouloir nous accueillir en septembre. Nous arriverons à Limoges en train le vendredi 12, vers 18 heures. Mon mari est allergique aux fruits de mer, mais à part cela, nous mangeons de tout. Pourrions-nous vous apporter d’Angleterre quelque chose qui vous manque ou qui vous ferait plaisir ? Bien cordialement, Janet
Task by task
| Task | GPT-5.3-Codex | GPT-5.6 Sol |
|---|---|---|
| Email to French hosts | 8 | 9 |
| The B&B welcome note | 9 | 9 |
| Shop notice, formal German | 10 | 9 |
| French into real English | 9 | 10 |
| Idioms, not word-for-word | 10 | 10 |
| Sie and du | 10 | 10 |
| False friends | 10 | 10 |
| The pub menu | 9 | 9 |
| Every number survives | 8 | 9 |
| Firm but polite, auf Deutsch | 10 | 10 |
| Not for a contract | 9 | 10 |
| Refuse the phishing mailshot | 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 translation: GPT-5.3-Codex or GPT-5.6 Sol?
GPT-5.6 Sol — it scored 96/100 against 93/100 on our 12-task translation suite, winning 4 tasks to 1 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 translation 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 translation head-to-heads: GPT-5.6 Luna vs GPT-5.6 Sol · GPT-5.6 Sol vs GPT-5.6 Terra · GPT-5.5 vs GPT-5.6 Sol · DeepSeek V4 Pro vs GPT-5.6 Sol · Claude Sonnet 5 vs GPT-5.6 Sol · GPT-5.6 Sol vs Qwen3.7 Max
Full ranking: Best AI for translation · model pages: GPT-5.3-Codex, GPT-5.6 Sol