DeepSeek V4 vs DeepSeek V4.1 Flash

DeepSeek · China  |  DeepSeek · China · Updated June 2026

Quick verdict

Both are DeepSeek models. DeepSeek V4.1 Flash is the newer, generally stronger default; reach for DeepSeek V4 when a specific cost or latency profile matters more than the latest capabilities.

DeepSeek V4 and DeepSeek V4.1 Flash are both DeepSeek models, so the real question is not which lab to trust but which tier fits your workload and budget. DeepSeek V4 is china's open-weight price earthquake — near-frontier capability at roughly a twelfth of GPT-5.5's cost. DeepSeek V4.1 Flash is deepSeek's September 2026 flash-tier update adds native vision and a 1M-token window to its cost-efficient V4 line, at $0.15/$0.60 per million tokens. Since both come from the same lab, the comparison below focuses on the tier-and-cost trade-offs that actually separate them.

Key differences at a glance

Side-by-side specs

SpecDeepSeek V4DeepSeek V4.1 Flash
ProviderDeepSeek (China) DeepSeek (China)
ReleasedApril 24, 2026 September 10, 2026
Context window1M (~1,500 pages) 1.05M tokens (~1,573 pages)
Price (in/out)$0.66/$1.98 per 1M tokens $0.15/$0.6 per 1M tokens
Open weight?Yes — self-hostable Yes — self-hostable
Modalitiestext, code text, image
SWE-Bench Verified80.6% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Near-frontier coding at ~1/12 the cost

DeepSeek V4

DeepSeek V4.1 Flash is comparatively weak here — positioned as a cost/speed tier, not a frontier-reasoning flagship — DeepSeek kept V4-Pro running in parallel rather than replacing it outright

Open MIT-licensed weights you can self-host

DeepSeek V4

DeepSeek V4 lists open MIT-licensed weights you can self-host among its strengths; DeepSeek V4.1 Flash does not.

No long-context surcharge

DeepSeek V4

DeepSeek V4 lists no long-context surcharge among its strengths; DeepSeek V4.1 Flash does not.

Software engineering (DeepSWE v1.1: 74.2, essentially level with Claude Opus 5's 74.0)

DeepSeek V4.1 Flash

DeepSeek's September 2026 flash-tier update adds native vision and a 1M-token window to its cost-efficient V4 line, at $0.15/$0.60 per million tokens — and it runs cheaper at $0.15/$0.6 per 1M tokens.

1M-token context window at a fraction of frontier pricing ($0.15/$0.60 per million tokens off-peak)

DeepSeek V4.1 Flash

DeepSeek's September 2026 flash-tier update adds native vision and a 1M-token window to its cost-efficient V4 line, at $0.15/$0.60 per million tokens — and it is the newer of the two.

Native multimodal vision, added over the text-only V4-Flash it replaces on most traffic

DeepSeek V4.1 Flash

DeepSeek V4 is comparatively weak here — this generic 'V4' entry mirrors DeepSeek V4-Pro's specs - see DeepSeek V4-Pro and DeepSeek V4-Flash for DeepSeek's actual named product tiers

Lowest cost at scale

DeepSeek V4.1 Flash

At $0.15/$0.6 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 V4.1 Flash

At $0.15/$0.6 per 1M tokens it undercuts DeepSeek V4, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

DeepSeek V4.1 Flash

Larger 1.05M tokens window fits more in one prompt.

Anyone whose priority is near-frontier coding at ~1/12 the cost

DeepSeek V4

It is specifically built for that.

Anyone whose priority is software engineering (deepswe v1.1: 74.2, essentially level with claude opus 5's 74.0)

DeepSeek V4.1 Flash

That is its strongest area.

DeepSeek V4: where it fits

China's open-weight price earthquake — near-frontier capability at roughly a twelfth of GPT-5.5's cost. Released April 24, 2026 by DeepSeek, it is built for near-frontier coding at ~1/12 the cost, open MIT-licensed weights you can self-host, no long-context surcharge, and highest LiveCodeBench result.

Its trade-offs are real: this generic 'V4' entry mirrors DeepSeek V4-Pro's specs - see DeepSeek V4-Pro and DeepSeek V4-Flash for DeepSeek's actual named product tiers, trails the very best on hardest agentic coding, and text/code focused, less multimodal. At $0.66 in / $1.98 out per million tokens, it sits in the budget price band.

DeepSeek V4.1 Flash: where it fits

DeepSeek's September 2026 flash-tier update adds native vision and a 1M-token window to its cost-efficient V4 line, at $0.15/$0.60 per million tokens. Released September 10, 2026 by DeepSeek, it is built for software engineering (DeepSWE v1.1: 74.2, essentially level with Claude Opus 5's 74.0), 1M-token context window at a fraction of frontier pricing ($0.15/$0.60 per million tokens off-peak), native multimodal vision, added over the text-only V4-Flash it replaces on most traffic, and mIT-licensed open weights, self-hostable.

Its trade-offs: the $0.15/$0.60 pricing is an off-peak rate — cost reportedly doubles during peak-demand hours, new Causal Encoder-Decoder architecture (8B active for input, 16B for output) is unproven at broader scale versus DeepSeek's mainline V4/V4-Pro line, and positioned as a cost/speed tier, not a frontier-reasoning flagship — DeepSeek kept V4-Pro running in parallel rather than replacing it outright. At $0.15 in / $0.6 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

Because DeepSeek V4 and DeepSeek V4.1 Flash come from the same lab (DeepSeek), they share the same training philosophy and ecosystem — the decision is purely tier vs. cost. DeepSeek V4.1 Flash is the more capable, more recent option; the other earns its place only when its price or latency profile fits a specific job better. Most teams should default to DeepSeek V4.1 Flash and drop down only with a concrete reason.

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Frequently asked questions

Is DeepSeek V4 or DeepSeek V4.1 Flash better for coding?

Public SWE-Bench figures are not available for DeepSeek V4.1 Flash, so the honest test is your own repository — run an identical real bug through both. By design, DeepSeek V4 leans toward near-frontier coding at ~1/12 the cost while DeepSeek V4.1 Flash leans toward software engineering (deepswe v1.1: 74.2, essentially level with claude opus 5's 74.0), and that positioning usually predicts which feels better on your codebase.

Which is cheaper, DeepSeek V4 or DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash is cheaper — $0.66/$1.98 per 1M tokens vs $0.15/$0.6 per 1M tokens, roughly 4.4× apart on input.

Which has the bigger context window?

Effectively neither — 1M vs 1.05M tokens is a difference of a few percent. Remember advertised ≠ usable: recall typically degrades before the ceiling.

Should I upgrade from DeepSeek V4 to DeepSeek V4.1 Flash?

Since both are DeepSeek models, the newer one (DeepSeek V4.1 Flash) is usually the better default unless you need a specific cost or latency profile from the other.

Which is newer, DeepSeek V4 or DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash — released September 10, 2026, about 5 months after DeepSeek V4.

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.