DeepSeek V4 Pro vs GPT-5.3-Codex for emotional support

The verdict

Effectively a dead heat: 9795

Same 12 emotional support tasks, marked blind by three rival labs. DeepSeek V4 Pro took 4 tasks, GPT-5.3-Codex took 2, 6 tied. Tested 16 Aug 2026.

Where they differed most

The task — The dog died

Your friend's dog Alfie died this morning after 14 years. Write the text message (max 60 words) you would actually send. Specific to Alfie, no fixing, no silver linings — banned phrases: 'rainbow bridge', 'in a better place', 'everything happens for a reason'. It should ask for nothing except what she wants to give.

I just heard about Alfie. I know he was your boy for 14 years, and I’m so sorry. I’m not going to ask anything of you. I’m here to hear Alfie stories, sit in the quiet, or whatever you want. No need to reply.
I’m so sorry about Alfie. Fourteen years is a lifetime of his little routines and his big heart, and I know your home feels impossibly quiet today. I’m holding you both in my heart. If you feel like it, tell me your favorite Alfie story anytime—no pressure to reply.

Task by task

TaskDeepSeek V4 ProGPT-5.3-Codex
The dog died109
Redundant at 551010
She said no advice1010
After the miscarriage109
Driving test at 9am89
First Father's Day after109
The 3am calls1010
Days without speaking910
Stop apologising1010
Not a diagnosis99
Her promotion, your rejection1010
The 1am message109

Full receipts: DeepSeek V4 Pro, GPT-5.3-Codex · judges claude-sonnet-5, gemini-3.1-pro-preview, gpt-5.6-terra

Questions people ask

Which is better for emotional support: DeepSeek V4 Pro or GPT-5.3-Codex?

Effectively a dead heat: DeepSeek V4 Pro edged it 97/100 to 95/100 on our emotional support suite — too close to matter, so pick on price or the product you already use.

How was this tested?

Both models answered the identical published emotional support 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 emotional support head-to-heads: Claude Sonnet 5 vs DeepSeek V4 Pro · Claude Sonnet 5 vs GPT-5.3-Codex · DeepSeek V4 Pro vs GPT-5.5 · GPT-5.3-Codex vs GPT-5.5 · Claude Fable 5 vs DeepSeek V4 Pro · Claude Opus 4.8 vs DeepSeek V4 Pro

Full ranking: Best AI for emotional support · model pages: DeepSeek V4 Pro, GPT-5.3-Codex