DeepSeek: DeepSeek V4.1 Flash 1017 vs Google: Gemini 2.5 Flash Lite Preview 09-2025

Neither wins outright: DeepSeek: DeepSeek V4.1 Flash 1017 is the pick when you need log-probabilities, Google: Gemini 2.5 Flash Lite Preview 09-2025 when cost matters at scale.

Key numbers

SpecDeepSeek: DeepSeek V4.1 Flash 1017Google: Gemini 2.5 Flash Lite Preview 09-2025
ProviderDeepSeekGoogle
Input price (per 1M tokens)$0.15$0.10
Output price (per 1M tokens)$0.60$0.40
Blended price (3:1 input/output)$0.26$0.18
Cheaper than … of all models we track64%71%
Context window1.0M tokens (~1,573 pages)1.0M tokens (~1,573 pages)
Larger context than … of all models80%80%
Max output per response393K tokens (~294,900 words)66K tokens (~49,200 words)
Input typestext, imagetext, image, file, audio, video
Output typestexttext
Free variantNoNo
Listed since2026-10-172025-09-25
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What it costs for real workloads

Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.

Workload (per month)DeepSeek: DeepSeek V4.1 Flash 1017Google: Gemini 2.5 Flash Lite Preview 09-2025Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$23.25$15.50Google: Gemini 2.5 Flash Lite Preview 09-2025 saves $7.75
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$24.00$16.00Google: Gemini 2.5 Flash Lite Preview 09-2025 saves $8.00
Coding / tool-using agent
2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens)
$25.20$16.80Google: Gemini 2.5 Flash Lite Preview 09-2025 saves $8.40
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$15.60$10.40Google: Gemini 2.5 Flash Lite Preview 09-2025 saves $5.20
Long-document analysis
500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens)
$8.10$5.40Google: Gemini 2.5 Flash Lite Preview 09-2025 saves $2.70

Capabilities side by side

CapabilityDeepSeek: DeepSeek V4.1 Flash 1017Google: Gemini 2.5 Flash Lite Preview 09-2025What it lets you do
Tool / function calling✓ Yes✓ Yescall your APIs and run agent loops
Structured output (JSON schema)✓ Yes✓ Yesreturn JSON that validates against your schema
Reasoning / thinking mode✓ Yes✓ Yesspend extra tokens thinking before answering hard problems
Image input✓ Yes✓ Yesread screenshots, charts and scanned pages
Audio input—✓ Yestake speech or audio directly
File / PDF input—✓ Yesaccept documents without your own parsing step
Image output——generate images, not just text
Built-in web search——answer from live web results
Seed (reproducible sampling)✓ Yes✓ Yesrepeat a generation for tests and evals
Log-probabilities✓ Yes—read token confidence for classification and scoring

From each model's published parameters and input/output types. “—” means not advertised, not proven absent.

Price history

Which should you choose?

Choose DeepSeek: DeepSeek V4.1 Flash 1017 if…

  • you need log-probabilities — to read token confidence for classification and scoring; Google: Gemini 2.5 Flash Lite Preview 09-2025 does not advertise it
  • you generate long outputs in one go — up to 393K tokens (about 294,900 words) per response
  • you want the newer model — released 2026-10-17, 13 months after the other

Choose Google: Gemini 2.5 Flash Lite Preview 09-2025 if…

  • cost matters at scale — it is 33% cheaper on a typical 3:1 input/output mix ($15.50 vs $23.25 a month for 50,000 support chats)
  • you need audio input — to take speech or audio directly; DeepSeek: DeepSeek V4.1 Flash 1017 does not advertise it
  • you need file / PDF input — to accept documents without your own parsing step; DeepSeek: DeepSeek V4.1 Flash 1017 does not advertise it

Frequently asked questions

Is DeepSeek: DeepSeek V4.1 Flash 1017 better than Google: Gemini 2.5 Flash Lite Preview 09-2025?

Neither wins outright: DeepSeek: DeepSeek V4.1 Flash 1017 is the pick when you need log-probabilities, Google: Gemini 2.5 Flash Lite Preview 09-2025 when cost matters at scale. In short: DeepSeek: DeepSeek V4.1 Flash 1017 when you need log-probabilities, you generate long outputs in one go, you want the newer model; Google: Gemini 2.5 Flash Lite Preview 09-2025 when cost matters at scale, you need audio input, you need file / PDF input.

Which is cheaper, DeepSeek: DeepSeek V4.1 Flash 1017 or Google: Gemini 2.5 Flash Lite Preview 09-2025?

Google: Gemini 2.5 Flash Lite Preview 09-2025 is cheaper: $0.18 vs $0.26 per 1M tokens at a typical 3:1 input/output mix, 33% less. For 50,000 support conversations a month that is $15.50 against $23.25.

How much do DeepSeek: DeepSeek V4.1 Flash 1017 and Google: Gemini 2.5 Flash Lite Preview 09-2025 cost per million tokens?

DeepSeek: DeepSeek V4.1 Flash 1017 costs $0.15 per 1M input tokens and $0.60 per 1M output tokens; Google: Gemini 2.5 Flash Lite Preview 09-2025 costs $0.10 input and $0.40 output. Output tokens are billed separately, so long answers shift the gap.

Which has the bigger context window, DeepSeek: DeepSeek V4.1 Flash 1017 or Google: Gemini 2.5 Flash Lite Preview 09-2025?

Both take 1.0M tokens per request — roughly 1,573 pages of text.

Do DeepSeek: DeepSeek V4.1 Flash 1017 and Google: Gemini 2.5 Flash Lite Preview 09-2025 support function calling and JSON output?

Tool calling — DeepSeek: DeepSeek V4.1 Flash 1017: yes, Google: Gemini 2.5 Flash Lite Preview 09-2025: yes. JSON-schema structured output — DeepSeek: DeepSeek V4.1 Flash 1017: yes, Google: Gemini 2.5 Flash Lite Preview 09-2025: yes.

Can DeepSeek: DeepSeek V4.1 Flash 1017 or Google: Gemini 2.5 Flash Lite Preview 09-2025 read images?

Yes, both accept image input.

Is DeepSeek: DeepSeek V4.1 Flash 1017 or Google: Gemini 2.5 Flash Lite Preview 09-2025 free to use?

No free variant is listed for either; both are pay-per-token.

What is the maximum output length of DeepSeek: DeepSeek V4.1 Flash 1017 and Google: Gemini 2.5 Flash Lite Preview 09-2025?

DeepSeek: DeepSeek V4.1 Flash 1017 can write up to 393K tokens (about 294,900 words) per response; Google: Gemini 2.5 Flash Lite Preview 09-2025 up to 66K (about 49,200 words).

When were DeepSeek: DeepSeek V4.1 Flash 1017 and Google: Gemini 2.5 Flash Lite Preview 09-2025 released?

DeepSeek: DeepSeek V4.1 Flash 1017 was listed on 2026-10-17; Google: Gemini 2.5 Flash Lite Preview 09-2025 on 2025-09-25.

About the two models

Google

Google: Gemini 2.5 Flash Lite Preview 09-2025

Gemini 2.5 Flash-Lite is a lightweight reasoning model in the Gemini 2.5 family, optimized for ultra-low latency and cost efficiency. It offers improved throughput, faster token generation, and better performance across common benchmarks compared to earlier Flash models. By default, "thinking" (i.e. multi-pass reasoning) is disabled to prioritize speed, but developers can enable it via the [Reasoning API parameter](https://openrouter.ai/docs/use-cases/reasoning-tokens) to selectively trade off cost for intelligence.

Full Google: Gemini 2.5 Flash Lite Preview 09-2025 specs →

Compare DeepSeek: DeepSeek V4.1 Flash 1017 with other models

Compare Google: Gemini 2.5 Flash Lite Preview 09-2025 with other models

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