DeepSeek V4.1 Flash API

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The DeepSeek V4.1 Flash API is DeepSeek's newest Flash route, and OmniaKey already serves the October 17, 2026 (1017) build: 1M context, native image input, and thinking modes from low to max.

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Input · USD / 1M tokens$0.15 USD
Output · USD / 1M tokens$0.6 USD
Context1M
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What are we making today?

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What this model is for

The DeepSeek V4.1 Flash API is DeepSeek's newest Flash route, and OmniaKey already serves the October 17, 2026 (1017) build: 1M context, native image input, and thinking modes from low to max.

DeepSeek V4.1 Flash is the fast-tier model of DeepSeek's V4 family on OmniaKey, listed as deepseek-flash and serving the October 17, 2026 build that DeepSeek labels 1017. It pairs a 1M context window with native image input, tool use and reasoning effort from low to max, defaulting to high. In the catalog it sits beside DeepSeek V4 Pro as the cheaper member of the family, and it is the only one of the two that lists vision.

The 1017 update kept the id, so existing calls already run the newer build. Choose it for high-volume extraction, screenshot reading and searches inside very long logs, where output tokens dominate the bill and a long reasoning run is the main risk. Keep DeepSeek V4 Pro for text-only work that your own comparisons show it handles better, and keep the older V4 Flash id only where a pinned name matters more than window or image support.

Our release-day spot check ran it against V4 Pro on five tasks: a 30-test arithmetic parser, invoice extraction, four parallel calls, three codes hidden in a 263K-token log, and a bar chart. It matched V4 Pro on the four tasks both could run and finished each one sooner, and it answered the chart questions that V4 Pro cannot take as input. One run per task on one afternoon is a spot check, and the timings are recorded in the test list.

Choose it for high-volume coding and agent loops that also read screenshots or diagrams, and for long sessions where the cheaper output rate matters — 1017 shipped under the same deepseek-flash ID, so existing calls already run it.

Best-fit coding workloads

Invoice fields to JSON

Pull ten fields from a supplier email that mixes German and English, writes numbers the European way and applies a discount to one line only. Set reasoning effort to low for this shape of job, ask for strict JSON, and check the totals against the source before writing rows.

Chart and screenshot reading

Ask four or five numbered questions about a single image: highest month, lowest, average and one gap between series. Images are resized into a fixed token budget, so phrase each question around a number that appears in the chart and compare the reply with the pixels yourself.

Search inside very long logs

Keep a quarter-million-token log in one request and ask for specific codes with their line numbers and surrounding lines. The 1M window holds the file without chunking, and streaming keeps a long turn alive. Asking for the matched line works better than asking for a summary of the whole run.

Hands-on notes

Checked on 2026-10-27 through the OmniaKey API with one standard coding prompt (median of 3 runs) and three capability probes.

Output tokens for our standard coding prompt, reasoning included: 3,754
Cost of that output at current prices: $0.0023
JSON mode: Passed
Tool calling: Passed
Image input: Passed

In our 30-test parser task, DeepSeek V4.1 Flash passed every case in 88 seconds, while V4 Pro took 20.7 minutes for the same result.
Read the test
When we ran our invoice email extraction task, DeepSeek V4.1 Flash returned all ten fields in 5.2 seconds against 22.1 seconds for V4 Pro.
Read the test
Our four-way tool-call test asked DeepSeek V4.1 Flash for two cities' weather and local times, and all four calls came back right in 2.6 seconds.
Read the test
We hid three current badge codes in a 263K-token log, and DeepSeek V4.1 Flash returned all three in 24.1 seconds.
Read the test
When we sent DeepSeek V4.1 Flash a bar chart image, it answered all four questions correctly in 3.8 seconds.
Read the test

Technical specification

Catalog facts and integration details verified for this route.

Model ID: deepseek-flash
Context: 1M
Inputs and tools: Vision · Tool use · Fast responses
API endpoint: /v1/chat/completions
Cache hit / 1M: $0.003 USD
Coding clients: Claude Code · Codex · Cursor · Cline · Aider

Limits to plan around

DeepSeek caps each image at 1,024 input tokens after resizing, so a dense table or a page of small print can lose detail. Ask for the field you need and check it against the picture.
With tools attached in thinking mode, a follow-up request has to send the earlier reasoning_content back; DeepSeek's guide says leaving it out returns HTTP 400.
Fill-in-the-middle completion runs only with thinking switched off, so an editor feature built on that mode needs a separate non-thinking path.
DeepSeek treats deepseek-v4-flash and deepseek-v4-flash-vision-exp as temporary aliases of this build on its own API, so pin deepseek-flash in code instead of a name that may be withdrawn.

Compare nearby models

Compare workload fit and current listed token rates before choosing a route.

Model	Best for	Context	Input	Output
DeepSeek V4.1 FlashThis page deepseek-flash	High-volume coding, extraction and image reading at the lower DeepSeek tier, with reasoning you can lower.	1M	$0.15 USD Official price $0.15 USD	$0.6 USD Official price $0.6 USD
DeepSeek V4 Pro deepseek-v4-pro	Text-only work where DeepSeek's flagship answers better on your own tasks and can absorb the higher rate.	1M	$0.435 USD Official price $0.435 USD	$0.87 USD Official price $0.87 USD
DeepSeek V4 Flash deepseek-v4-flash	Plain-text loops on the older Flash id, which the catalog lists without a context window or vision.		$0.14 USD Official price $0.14 USD	$0.28 USD Official price $0.28 USD

SDK quickstarts

Use one base URL and model ID from cURL, Python, or TypeScript.

Streaming chat completion

curl https://api.omniakey.com/v1/chat/completions \
  -H "Authorization: Bearer $OMNIAKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek-flash",
    "messages": [
      {"role": "user", "content": "Review this pull request"}
    ],
    "stream": true
  }'

Estimate token cost

Enter expected input and output tokens to compare current listed rates.

Input tokensOutput tokens

OmniaKey estimate: $0.027
Official-rate estimate: $0.027
Estimated savings: $0.00

Estimate covers input and output tokens only. Cache usage, retries, tools, and client-side token accounting can change the final charge.

Related coding guides

Deeper selection, setup, and troubleshooting guidance for this model family.

DeepSeek V4.1 Flash 1017 Review: What Changed, Tested vs V4 Pro

Same ID, same price, higher scores. We ran it against V4 Pro.

Read guide

DeepSeek V4.1 Flash Review

DeepSeek's new Flash route is cheaper and stronger on several agent tests, but the official evidence does not show a win on every benchmark.

Read guide

Sources and verification

Model facts and links were checked on 2026-10-27. Provider documentation remains the authority for upstream behavior.

Frequently asked questions

How much does DeepSeek V4.1 Flash cost on OmniaKey?

OmniaKey charges the official rate: $0.15 USD per 1M input tokens and $0.6 USD per 1M output tokens, in USD.

What is the context window for DeepSeek V4.1 Flash?

The listed context window is 1M. Actual usable limits can also depend on the client and upstream request format.

What is DeepSeek V4.1 Flash 1017?

It is DeepSeek's October 17, 2026 update to V4.1 Flash, and it is the build that deepseek-flash has served since then. DeepSeek's update log lists it as a minor release rather than a new model, and the catalog keeps one row for the id, marked as new, with the 1M window, image input and tool use that the September launch brought.

Does my API code need updating for 1017?

No. DeepSeek's update log for October 17 calls it a minor update and says the calling method is unchanged, so a request that already names deepseek-flash keeps working and simply reaches the newer build. What changed is the build behind the id, not the request shape or the capability list: 1M context, image input, tool use and thinking effort from low to max are as before. In our release-day spot check it matched V4 Pro on all four tasks both models could run.

How do I call DeepSeek V4.1 Flash on OmniaKey?

Send a request to https://api.omniakey.com/v1/chat/completions with deepseek-flash as the model. The catalog lists claude-code, codex, cursor, cline and aider for this id, each set up with the base URL and an OmniaKey key. For Claude Code, point ANTHROPIC_BASE_URL at https://api.omniakey.com and use the same key.

Can DeepSeek V4.1 Flash read images?

Yes. The catalog lists vision for this id and not for V4 Pro, and DeepSeek's image guide caps each image at 1,024 input tokens after resizing, with up to 600 images in one request. It reads charts, screenshots and scanned text; it does not generate images, and small print still deserves a second check.

How did V4.1 Flash compare with V4 Pro in your tests?

It matched V4 Pro's answers on the four tasks both could run and finished each one sooner. Both passed all 30 parser tests, both returned ten invoice fields, and both made the four tool calls in one reply. It also read a bar chart that V4 Pro has no image input for, and the timings are listed with the test results.

Which reasoning effort should I set?

Thinking is on by default at high, and DeepSeek exposes low, high and max. Use low for extraction and classification, where the answer is already well specified, keep high for agent loops, and try max only on tasks where your own results justify the extra output. Effort changes output tokens, which carry their own rate.