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DeepSeek V4 Pro vs GPT-5.5
Of the 2 public leaderboards that rate both, DeepSeek V4 Pro scores higher on 1 and GPT-5.5 on 1. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, DeepSeek V4 Pro is at 19.9 and GPT-5.5 at 41.7 (out of 100). On each maker's API, DeepSeek V4 Pro costs $0.66 / $1.98 per 1M tokens (input / output) and GPT-5.5 $5 / $30.
Scores as published by each board; table composed November 8, 2026.
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Leaderboard by leaderboard
| Board | DeepSeek V4 Pro | GPT-5.5 | Higher |
|---|---|---|---|
| LMArena Elo (community votes) | 1,581.6 | 1,512.6 | DeepSeek V4 Pro |
| SimpleBench AVG@5 % (private set) | 50.9 | 76.9 | GPT-5.5 |
Raw scores are each board's own scale, so compare within a row, not across rows. Full table: the bench index.
For coding
On the ArtificialWatch coding index, DeepSeek V4 Pro is at 40 (#27 of 45) and GPT-5.5 at 37.8 (#29). DeepSeek V4 Pro scores higher on 1 of the 2 coding boards that rate both and GPT-5.5 on 1.
| Coding board | DeepSeek V4 Pro | GPT-5.5 |
|---|---|---|
| LMArena · Coding | 1,469.1 | 1,494.2 |
| Vals Vibe Code Bench | 82.3 | 69.8 |
DeepSeek V4 Pro at a glance
- Developer
- DeepSeek
- Status
- Live since April 24, 2026
- API price
- $0.66 input / $1.98 output per 1M tokens · DeepSeek, deepseek-v4-pro
- Context window
- 1.05M tokens
Live · open weights · superseded by V4.1 Flash — per DeepSeek's own changelog rather than our own reading, deepseek-v4-flash routes to V4.1 Flash; the matching deepseek-v4-pro cutover set for 04:00 UTC Sep 14 was reversed on its eve and V4 Pro is still served at unchanged billing, which is search-grade too — but our own bench refresh still scored deepseek-v4-pro-0813 as a separate model on Sep 16 · our sweep read the bare deepseek-flash alias on Sep 10 at $0.15/$0.60 per 1M, 1M ctx.
DeepSeek V4-Pro lands at $0.435/$0.87 — and "model names remain unchanged" hides a 2.7x price fork
2026-08-13 · DeepSeek launched V4-Pro today on app, web and API. The headline features are agent upgrades, selectable reasoning effort across V4-Pro and V4-Flash, and native OpenAI Responses API support optimised for Codex. The line worth reading twice is the quiet one: "Model names remain unchanged."
GPT-5.5 at a glance
- Developer
- OpenAI
- Status
- Live since April 24, 2026
- API price
- $5 input / $30 output per 1M tokens · OpenAI, gpt-5.5
- Context window
- 1.05M tokens
Live.
DeepSeek V4 Pro vs GPT-5.5: quick answers
Which is better, DeepSeek V4 Pro or GPT-5.5?
It depends on what you measure. Of the 2 public leaderboards that rate both, DeepSeek V4 Pro scores higher on 1 and GPT-5.5 on 1. DeepSeek V4 Pro's widest lead is on LMArena; GPT-5.5's widest lead is on SimpleBench. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, DeepSeek V4 Pro is at 19.9 and GPT-5.5 at 41.7 (out of 100).
Which is cheaper, DeepSeek V4 Pro or GPT-5.5?
DeepSeek V4 Pro is cheaper on both input and output. On each vendor's own API, DeepSeek V4 Pro is $0.66 input / $1.98 output per million tokens and GPT-5.5 is $5 input / $30 output per million tokens. GPT-5.5's rate rises for prompts over 272K tokens. Prices as published in the models.dev catalog, as of 2026-11-08.
Which has the bigger context window, DeepSeek V4 Pro or GPT-5.5?
GPT-5.5, at 1.05M tokens against DeepSeek V4 Pro's 1.05M, as each vendor lists it.
How do DeepSeek V4 Pro and GPT-5.5 compare for coding?
On the ArtificialWatch coding index, DeepSeek V4 Pro is at 40 (#27 of 45) and GPT-5.5 at 37.8 (#29). DeepSeek V4 Pro scores higher on 1 of the 2 coding boards that rate both and GPT-5.5 on 1.
Who makes DeepSeek V4 Pro and GPT-5.5?
DeepSeek V4 Pro is from DeepSeek; GPT-5.5 is from OpenAI.
Where do these numbers come from?
Each score is the leaderboard's own published figure, read by ArtificialWatch (table composed November 8, 2026). Boards measure different things, so raw scores are only comparable within a row.
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Also: the bench index · API pricing · what a workload costs on each · the wire