DeepSeek V3.2 vs GPT-5.5

DeepSeek · China  |  OpenAI · US · Updated June 2026

Quick verdict

Pick DeepSeek V3.2 for long-context efficiency via deepseek sparse attention (dsa) or agentic tool-use with thinking integrated into tool calls (thinking/non-thinking modes). Pick GPT-5.5 for terminal, cli and computer-use automation or long-horizon tool sequencing. Choose DeepSeek V3.2 if you need self-hosting or data privacy; GPT-5.5 if you want a managed API.

DeepSeek V3.2 (DeepSeek, China) and GPT-5.5 (OpenAI, US) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. DeepSeek V3.2 is a cost-efficient, open-weight (MIT) 685B-parameter MoE model whose DeepSeek Sparse Attention delivers GPT-5-comparable reasoning with far cheaper long-context inference. GPT-5.5 is openAI's first fully retrained base since GPT-4.5 — the terminal and computer-use champion. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecDeepSeek V3.2GPT-5.5
ProviderDeepSeek (China) OpenAI (US)
ReleasedDecember 1, 2025 April 23, 2026
Context window131K (~197 pages) 1M (~1,500 pages)
Price (in/out)$0.28/$0.42 per 1M tokens $5/$30 per 1M tokens
Open weight?Yes — self-hostable No — API only
Modalitiestext, code text, image, code
SWE-Bench Verified73.1% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Long-context efficiency via DeepSeek Sparse Attention (DSA)

DeepSeek V3.2

A core design strength of DeepSeek V3.2.

Agentic tool-use with thinking integrated into tool calls (thinking/non-thinking modes)

DeepSeek V3.2

A core design strength of DeepSeek V3.2.

Elite competition math and reasoning (AIME 2025 93.1, Codeforces 2386)

DeepSeek V3.2

A core design strength of DeepSeek V3.2.

Terminal, CLI and computer-use automation

GPT-5.5

A core design strength of GPT-5.5.

Long-horizon tool sequencing

GPT-5.5

A core design strength of GPT-5.5.

Strong agentic coding and reasoning

GPT-5.5

A core design strength of GPT-5.5.

Lowest cost at scale

DeepSeek V3.2

At $0.28/$0.42 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

GPT-5.5

Its 1M window is about 7.6× larger, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

DeepSeek V3.2

At $0.28/$0.42 per 1M tokens it undercuts GPT-5.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

GPT-5.5

Larger 1M window fits more in one prompt.

A team with data-privacy or self-hosting needs

DeepSeek V3.2

Open weights let you run it on your own hardware; GPT-5.5 is API-only.

Anyone whose priority is long-context efficiency via deepseek sparse attention (dsa)

DeepSeek V3.2

It is specifically built for that.

Anyone whose priority is terminal, cli and computer-use automation

GPT-5.5

That is its strongest area.

An enterprise with regional data-residency rules

GPT-5.5 or DeepSeek V3.2

Origin (China vs US) affects where data is processed and which compliance regime applies — check the provider's terms for your region.

DeepSeek V3.2: where it fits

A cost-efficient, open-weight (MIT) 685B-parameter MoE model whose DeepSeek Sparse Attention delivers GPT-5-comparable reasoning with far cheaper long-context inference. Released December 1, 2025 by DeepSeek, it is built for long-context efficiency via DeepSeek Sparse Attention (DSA), agentic tool-use with thinking integrated into tool calls (thinking/non-thinking modes), elite competition math and reasoning (AIME 2025 93.1, Codeforces 2386), and low-cost, open-weight (MIT) self-hosting.

Its trade-offs are real: text-only — no image, audio, or video input, and sWE-Bench Verified (73.1) trails the top closed coding models (Claude 4.5 Sonnet 77.2, Gemini 3 Pro 76.2). At $0.28 in / $0.42 out per million tokens, it sits in the budget price band.

GPT-5.5: where it fits

OpenAI's first fully retrained base since GPT-4.5 — the terminal and computer-use champion. Released April 23, 2026 by OpenAI, it is built for terminal, CLI and computer-use automation, long-horizon tool sequencing, strong agentic coding and reasoning, and browser-driving agents.

Its trade-offs: trails Opus 4.8 on hardest coding benchmarks, and tiered long-context pricing above 272K tokens. At $5 in / $30 out per million tokens, it sits in the premium price band.

The bottom line for this matchup

The defining split here is open vs. closed. DeepSeek V3.2 gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-5.5 gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.

Want both DeepSeek V3.2 and GPT-5.5 without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is DeepSeek V3.2 or GPT-5.5 better for coding?

Public SWE-Bench figures are not available for GPT-5.5, so the honest test is your own repository — run an identical real bug through both. By design, DeepSeek V3.2 leans toward long-context efficiency via deepseek sparse attention (dsa) while GPT-5.5 leans toward terminal, cli and computer-use automation, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, DeepSeek V3.2 or GPT-5.5?

DeepSeek V3.2 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-5.5 is API-metered at $5/$30 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.

Which has the bigger context window?

GPT-5.5 — 1M vs 131K, about 7.6× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both DeepSeek V3.2 and GPT-5.5 together?

Yes — a multi-model platform like LumiChats gives you DeepSeek V3.2, GPT-5.5 and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, DeepSeek V3.2 or GPT-5.5?

GPT-5.5 — released April 23, 2026, about 5 months after DeepSeek V3.2.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.