DeepSeek V4 Flash vs DeepSeek V4.1 Flash
什麼情況選哪一個
兩者皆具備 1,000,000 token 的上下文長度與 393,216 token 的最大輸出，並支援工具與推理，因此升級的考量在於輸入與價格的對比：deepseek-v4.1-flash 增加了圖片輸入，輸入費用為 $0.3（約 2.2x），輸出費用為 $1.2（約 4.4x），而僅支援文字的 deepseek-v4-flash 則分別為 $0.138 與 $0.275，不過前者的快取讀取費用較低，為 $0.006 對比 $0.0276。針對高用量文字聊天與程式碼任務，若較低的輸入與輸出費率及可關閉思考選項是重要考量，請繼續使用 deepseek-v4-flash；當您需要傳送圖片時，請轉換至 deepseek-v4.1-flash。
Benchmark 成績
供應商公布： Alibaba (Qwen) Anthropic ByteDance DeepSeek Google MiniMax Moonshot OpenAI Tencent Z.ai
定價
| DeepSeek V4 Flash | DeepSeek V4.1 Flash | Δ | |
|---|---|---|---|
| 輸入 / 1M tokens | $0.138 | $0.3 | 0.46× |
| 輸出 / 1M tokens | $0.275 | $1.2 | 0.23× |
| 快取讀取 / 1M tokens | $0.0276 | $0.006 | 4.6× |
| 快取寫入 | 不額外計費 | 不額外計費 | - |
費率取自網站建置時的即時目錄；各模型頁面都列有最新的價目。
兩者的相對位置：每 1M tokens 的輸入價格，涵蓋同一計費單位下全部 80 個聊天模型（對數尺度）
功能
| DeepSeek V4 Flash | DeepSeek V4.1 Flash | |
|---|---|---|
| 工具使用 | 是 | 是 |
| 思考控制 | 可設定 | 是，但供應商未公布調整參數 |
| 結構化輸出 | 是 | - |
| 提示詞快取 | 隱式（自動） | 隱式（自動） |
| 快取存活時間 | no fixed TTL (evicted when unused) | no fixed TTL (evicted when unused) |
| 最小快取前綴 | 未公布 | 未公布 |
規格
| DeepSeek V4 Flash | DeepSeek V4.1 Flash | |
|---|---|---|
| 輸入模態 | 文字 | 文字 圖像 |
| 輸出模態 | 文字 | 文字 |
| 發布日期 | 2026-04-24 | 2026-09-10 |
| 上下文視窗 | 1M | 1M |
| 最大輸出 | 393K | 393K |
| 思考參數 |
| - |
| 可接受的值 | thinking.type
reasoning_effort
| - |
| 預設值 | enabled, with reasoning_effort high some complex agent requests are automatically set to max | - |
規格摘錄自各供應商的文件；供應商沒有公布的項目就直接略過，不自行推測。 完整來源： DeepSeek V4 Flash · DeepSeek V4.1 Flash
同一段提示詞，兩個模型，經閘道實測
DeepSeek V4 Flash 通過 · 3 sentences
When reasoning is enabled, the model generates additional "chain-of-thought" tokens internally before producing the final answer, effectively doubling the total token count per request. Since our billing is based on tokens processed, this directly doubled your usage. Additionally, reasoning often requires more expensive model tiers or higher compute resources, further amplifying the cost increase.
輸出 154 tok (+85 思考) 延遲 3.1 s
DeepSeek V4.1 Flash 通過 · 3 sentences
Enabling reasoning changed the unit economics: the model now spends extra billable tokens internally to “think” before producing the answer, and those reasoning tokens are charged like output tokens even though users never see them. That added token generation—plus longer contexts and occasional retries on harder prompts—roughly doubled our cost per request. We can control this by capping reasoning depth, routing only complex queries to reasoning models, and caching common prompts to bring the bill back down.
輸出 423 tok (+327 思考) 延遲 14.6 s
是否照指令做（剛好三句，數得出來）、語氣是否貼合對象（寫給 CFO 看），以及下方 token 計量顯示出的隱藏思考計費落差。
DeepSeek V4 Flash 通過 · 8/8 cases
The bug is that the function counts the number of consecutive equal **pairs** (i.e., `cur` increments for each `i` where `xs[i] == xs[i-1]`), but it should return the **length** of the longest run. For a run of length `L`, the number of pairs is `L-1`, so the result is always one less than the correct value. This causes the function to return 0 for a single‑element list (expected 1) and to undercount runs that end at the last index (e.g., `[1,1]` returns 1 instead of 2). Additionally, runs of length 1 that are not part of any pair (such as a single element at the end of a list) are never considered because `best` is only updated when a pair is found. […]
輸出 2494 tok (+2227 思考) 延遲 19.4 s
DeepSeek V4.1 Flash 通過 · 8/8 cases
```python def longest_run(xs): if not xs: return 0 best = 1 cur = 1 for i in range(1, len(xs)): if xs[i] == xs[i - 1]: cur += 1 else: cur = 1 best = max(best, cur) return best ``` The bug is that `cur` is counting equal adjacent pairs, not elements in the current run: every time `xs[i] == xs[i - 1]`, the run length increases by one element, but the first element of the run was never counted, so all runs are undercounted by one. Also, `best` starts at `0`, so single-element inputs return `0` instead of `1`, and a one-element run ending at the last index is missed entirely.
輸出 918 tok (+733 思考) 延遲 11.4 s
修正是否真的正確（跑得起來）、說明的資訊密度，以及在範圍明確的任務上的 token 效率。
DeepSeek V4 Flash 通過 · 5/5 fields, guidance null
{ "company": "Meridian Robotics", "quarter": "Q3", "revenue_usd_m": 412, "growth_pct": null, "guidance": null }
輸出 1101 tok (+1054 思考) 延遲 10.2 s
DeepSeek V4.1 Flash 通過 · 5/5 fields, guidance "withheld pending the Q4 close"
{"company":"Meridian Robotics","quarter":"September quarter","revenue_usd_m":412,"growth_pct":11.0,"guidance":"withheld pending the Q4 close"}
輸出 1707 tok (+1667 思考) 延遲 15.1 s
是否遵守 schema（不自創欄位）、面對幻覺誘因的表現（題目明確不給 guidance），以及結構化輸出路徑的差異。
DeepSeek V4 Flash 通過 · 119 words, 0 banned, 1 question
We're thrilled to introduce Prompt Cache, a new feature for our API Gateway that stores prompt responses from any provider. When a user submits a prompt you've already processed, the system returns the cached result instantly—eliminating redundant API calls and reducing latency. This works across OpenAI, Anthropic, Google, and more, with automatic cache invalidation based on your rules. What does this mean for your budget? Fewer API calls directly lower your monthly spend. Additionally, response times drop by up to 80% for cached prompts, improving user experience. Developers can configure cache duration per provider, set TTLs, and bypass cache when needed. The feature is available now in your gateway dashboard. Start saving time and money with Prompt Cache.
輸出 2039 tok (+1887 思考) 延遲 15.6 s
DeepSeek V4.1 Flash 通過 · 116 words, 0 banned, 1 question
Today we're launching Cross-Provider Prompt Cache for our API gateway. It stores identical prompt requests and their responses across supported model providers, then serves cached results when a match is found. Teams can cut duplicate inference costs, reduce latency, and keep behavior consistent during provider failover. The cache works with configurable TTLs, per-route rules, and cache-key controls, so you decide what is reusable and what must stay fresh. Does your application send the same prompts to multiple providers? Now your gateway can answer many of those calls without another upstream request. Existing observability dashboards show hit rates, saved tokens, and estimated spend reduction. Enable it in the gateway console, set your policy, and start caching today.
輸出 917 tok (+770 思考) 延遲 9.0 s
是否遵守限制（字數上限、禁用詞清單、只能有一句問句）、文字風格的特徵，以及長度控制。
改一行程式碼就能在兩者之間切換
下面每個頁籤都列了這兩個模型 ID，要改的只有醒目標示的那兩行。端點、金鑰和請求格式都不變。
from openai import OpenAI
client = OpenAI(
base_url="https://synthorai.io/v1",
api_key="sk-syn-...",
)
resp = client.chat.completions.create(
model="deepseek-v4-flash",
# model="deepseek-v4.1-flash", # 取消這一行的註解，並把上一行註解掉
messages=[{"role": "user", "content": "Summarize this diff"}],
)
print(resp.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://synthorai.io/v1",
apiKey: "sk-syn-...",
});
const resp = await client.chat.completions.create({
model: "deepseek-v4-flash",
// model: "deepseek-v4.1-flash", // 取消這一行的註解，並把上一行註解掉
messages: [{ role: "user", content: "Summarize this diff" }],
});
console.log(resp.choices[0].message.content);curl https://synthorai.io/v1/chat/completions \
-H "Authorization: Bearer sk-syn-..." \
-H "Content-Type: application/json" \
-d '{
"model": "deepseek-v4-flash",
# "model": "deepseek-v4.1-flash", # 取消這一行的註解，並把上一行註解掉
"messages": [{"role": "user", "content": "Hello"}]
}'package main
import (
"context"
"fmt"
"github.com/openai/openai-go/v3"
"github.com/openai/openai-go/v3/option"
)
func main() {
client := openai.NewClient(
option.WithBaseURL("https://synthorai.io/v1"),
option.WithAPIKey("sk-syn-..."),
)
resp, _ := client.Chat.Completions.New(context.TODO(), openai.ChatCompletionNewParams{
Model: "deepseek-v4-flash",
// Model: "deepseek-v4.1-flash", // 取消這一行的註解，並把上一行註解掉
Messages: []openai.ChatCompletionMessageParamUnion{
openai.UserMessage("Summarize this diff"),
},
})
fmt.Println(resp.Choices[0].Message.Content)
}import com.openai.client.OpenAIClient;
import com.openai.client.okhttp.OpenAIOkHttpClient;
import com.openai.models.chat.completions.*;
OpenAIClient client = OpenAIOkHttpClient.builder()
.baseUrl("https://synthorai.io/v1")
.apiKey("sk-syn-...")
.build();
ChatCompletion resp = client.chat().completions().create(
ChatCompletionCreateParams.builder()
.model("deepseek-v4-flash")
// .model("deepseek-v4.1-flash") // 取消這一行的註解，並把上一行註解掉
.addUserMessage("Summarize this diff")
.build());
System.out.println(resp.choices().get(0).message().content().orElse(""));常見問題
DeepSeek V4 Flash 和 DeepSeek V4.1 Flash 哪個比較便宜？
以「輸入 / 1M tokens」來看，DeepSeek V4 Flash 比較便宜（$0.138 對 $0.3，相差 2.2×）。其他項目的結果可能相反，完整價目請看上表；實際成本要看你的用量組合。
可以只串接一次，就對 DeepSeek V4 Flash 和 DeepSeek V4.1 Flash 做 A/B 測試嗎？
可以。兩個模型都走同一個 OpenAI 相容端點，用的也是同一把 API 金鑰，切換時只要改一行裡的模型名稱字串。你可以把一部分流量分別導到兩邊，再直接比較帳單。
DeepSeek V4 Flash 與 DeepSeek V4.1 Flash 支援提示詞快取嗎？
支援。兩者的快取讀取費率都低於輸入費率，所以前綴已經進快取的工作負載，實際成本會比官網價算出來的低。確切的快取讀取價格請見上方定價表。