Claude Opus 5.5 vs DeepSeek V4-Pro

Anthropic · US  |  DeepSeek · China · Updated June 2026

Quick verdict

Pick Claude Opus 5.5 for performs at roughly claude fable 5.1's level on most work, at 40% lower typical workload cost than opus 5 or anthropic reports it surpasses fable 5.1 on agentic coding, knowledge work, computer use, visual chart recognition, and multidisciplinary reasoning. Pick DeepSeek V4-Pro for open-weight 1.6t moe (~49b active) — deepseek's largest, self-hostable or 1m-token context with up to 384k output tokens. Choose DeepSeek V4-Pro if you need self-hosting or data privacy; Claude Opus 5.5 if you want a managed API.

Claude Opus 5.5 (Anthropic, US) and DeepSeek V4-Pro (DeepSeek, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. Claude Opus 5.5 is anthropic's September 22, 2026 update: Fable 5.1-level performance at 40% lower cost than Opus 5, with faster output and cheaper caching. DeepSeek V4-Pro is deepSeek's 1.6-trillion-parameter open-weight model at $0.435/$0.87 — strong open-weight coding and a 1M context at a fraction of flagship prices. They diverge most on price and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecClaude Opus 5.5DeepSeek V4-Pro
ProviderAnthropic (US) DeepSeek (China)
ReleasedSeptember 22, 2026 April 24, 2026
Context window1M tokens (~1,500 pages) 1M (~1,500 pages)
Price (in/out)$4/$20 per 1M tokens $0.66/$1.98 per 1M tokens
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Performs at roughly Claude Fable 5.1's level on most work, at 40% lower typical workload cost than Opus 5

Claude Opus 5.5

Anthropic's September 22, 2026 update: Fable 5.1-level performance at 40% lower cost than Opus 5, with faster output and cheaper caching — and it is the newer of the two.

Anthropic reports it surpasses Fable 5.1 on agentic coding, knowledge work, computer use, visual chart recognition, and multidisciplinary reasoning

Claude Opus 5.5

Claude Opus 5.5 lists anthropic reports it surpasses Fable 5.1 on agentic coding, knowledge work, computer use, visual chart recognition, and multidisciplinary reasoning among its strengths; DeepSeek V4-Pro does not.

Pricing cut to $4/$20 per million tokens (20% below Opus 5's $5/$25), cache reads down 60% to $0.20/MTok

Claude Opus 5.5

Claude Opus 5.5 lists pricing cut to $4/$20 per million tokens (20% below Opus 5's $5/$25), cache reads down 60% to $0.20/MTok among its strengths; DeepSeek V4-Pro does not.

Open-weight 1.6T MoE (~49B active) — DeepSeek's largest, self-hostable

DeepSeek V4-Pro

Open weights make this possible at all — Claude Opus 5.5 is API-only, so it cannot leave the vendor's servers.

1M-token context with up to 384K output tokens

DeepSeek V4-Pro

Claude Opus 5.5 is comparatively weak here — like Opus 5, the headline 1M-token context is not uniformly available across every platform and plan — some API paths default to a smaller window

Permanent low pricing at $0.435/$0.87 per million, set May 2026

DeepSeek V4-Pro

DeepSeek's 1.6-trillion-parameter open-weight model at $0.435/$0.87 — strong open-weight coding and a 1M context at a fraction of flagship prices — and it runs cheaper at $0.66/$1.98 per 1M tokens.

Lowest cost at scale

DeepSeek V4-Pro

At $0.66/$1.98 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Which should you pick?

A cost-sensitive startup shipping high volume

DeepSeek V4-Pro

At $0.66/$1.98 per 1M tokens it undercuts Claude Opus 5.5, and on millions of tokens that margin decides the monthly bill.

A team with data-privacy or self-hosting needs

DeepSeek V4-Pro

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

Anyone whose priority is performs at roughly claude fable 5.1's level on most work, at 40% lower typical workload cost than opus 5

Claude Opus 5.5

It is specifically built for that.

Anyone whose priority is open-weight 1.6t moe (~49b active) — deepseek's largest, self-hostable

DeepSeek V4-Pro

That is its strongest area.

An enterprise with regional data-residency rules

Claude Opus 5.5 or DeepSeek V4-Pro

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

Claude Opus 5.5: where it fits

Anthropic's September 22, 2026 update: Fable 5.1-level performance at 40% lower cost than Opus 5, with faster output and cheaper caching. Released September 22, 2026 by Anthropic, it is built for performs at roughly Claude Fable 5.1's level on most work, at 40% lower typical workload cost than Opus 5, anthropic reports it surpasses Fable 5.1 on agentic coding, knowledge work, computer use, visual chart recognition, and multidisciplinary reasoning, pricing cut to $4/$20 per million tokens (20% below Opus 5's $5/$25), cache reads down 60% to $0.20/MTok, and output speed increased over 30% versus Opus 5.

Its trade-offs are real: not a reasoning-ceiling upgrade over Fable 5.1 — pitched as matching its performance at lower cost, not beating it outright, like Opus 5, the headline 1M-token context is not uniformly available across every platform and plan — some API paths default to a smaller window, and first model in the 5.5 line; Anthropic has signaled Sonnet 5.5 and Haiku 5.5 are still weeks away, so the lower tiers of the family aren't out yet. At $4 in / $20 out per million tokens, it sits in the mid price band.

DeepSeek V4-Pro: where it fits

DeepSeek's 1.6-trillion-parameter open-weight model at $0.435/$0.87 — strong open-weight coding and a 1M context at a fraction of flagship prices. Released April 24, 2026 by DeepSeek, it is built for open-weight 1.6T MoE (~49B active) — DeepSeek's largest, self-hostable, 1M-token context with up to 384K output tokens, permanent low pricing at $0.435/$0.87 per million, set May 2026, and sources place it near the top of open-weight coding, around 80 on SWE-Bench Verified.

Its trade-offs: independent SWE-Bench Verified placement is inconsistent across sources, pro and Pro-Max variants are quoted with different scores, text and code only — no image, audio or video, and overlaps DeepSeek V4 and V3.2 already in this comparison. At $0.66 in / $1.98 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

The defining split here is open vs. closed. DeepSeek V4-Pro gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Claude Opus 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 Claude Opus 5.5 and DeepSeek V4-Pro 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 Claude Opus 5.5 or DeepSeek V4-Pro better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Claude Opus 5.5 leans toward performs at roughly claude fable 5.1's level on most work, at 40% lower typical workload cost than opus 5 while DeepSeek V4-Pro leans toward open-weight 1.6t moe (~49b active) — deepseek's largest, self-hostable, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Opus 5.5 or DeepSeek V4-Pro?

DeepSeek V4-Pro is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Claude Opus 5.5 is API-metered at $4/$20 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?

Both advertise 1M tokens (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both Claude Opus 5.5 and DeepSeek V4-Pro together?

Yes — a multi-model platform like LumiChats gives you Claude Opus 5.5, DeepSeek V4-Pro 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, Claude Opus 5.5 or DeepSeek V4-Pro?

Claude Opus 5.5 — released September 22, 2026, about 5 months after DeepSeek V4-Pro.

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.