DeepSeek-V4-Flash-Vision-Exp API Guide: Multimodal Model Specs

DeepSeek-V4-Flash-Vision-Exp Overview

DeepSeek launched deepseek-v4-flash-vision-exp as its first official multimodal API model. It extends the text, reasoning, and agent capabilities of V4 Flash with image understanding, offering 1M token context, up to 384K output tokens, and a per-image cap of 384 tokens. The exp suffix denotes an experimental route that should not be treated as a long-term stable release.

Core Specifications

Benchmark Performance

Official benchmarks place Vision-Exp close to Opus-4.8 on multimodal agent tasks, with improvements over base V4 Flash in 8 of 9 directly comparable benchmarks. It leads on DeepSWE, Agents' Last Exam, and ZeroBench, but trails on Terminal Bench, NL2Repo, and DSBench-Hard. These are vendor-reported results under specific harness settings.

Three Ways to Send Images

Base64 Inline

Encode JPEG, PNG, GIF, or WebP as a data URL. Total request body limit is 48 MiB, single image up to 32 MiB.

External URL

Pass a publicly accessible HTTP(S) URL. Single image must be under 32 MiB and downloadable within 60 seconds. Avoid URLs requiring cookies, internal auth, or short-lived signatures.

Files API file_id

Upload images once and reuse via file_id across requests. Files API is free with a 64 MiB per-file limit and configurable expiry from 1 hour to 30 days. Image tokens are still billed per the official rules.

Chat Completions Example

curl https://api.deepseek.com/chat/completions -H "Authorization: Bearer $API_KEY" -H "Content-Type: application/json" -d '{"model":"deepseek-v4-flash-vision-exp","messages":[{"role":"user","content":[{"type":"text","text":"Describe this screenshot."},{"type":"image_url","image_url":{"url":"https://example.com/page.png"}}]}]}'

Mix text and multiple images freely. The Responses API uses input_image; Anthropic Messages use a separate endpoint. Do not copy Chat Completions payloads directly to other formats.

Production Checklist

• Use the exact model ID deepseek-v4-flash-vision-exp.
• Confirm the ID appears in your provider's live model directory before relying on it.
• Test base64, URL, and Files API separately — availability varies by gateway.
• Run smoke tests with small, non-sensitive images first.
• Log image count, image tokens, text tokens, output tokens, latency, and billing.
• Build scored eval sets for OCR, charts, layouts, and small text.
• Keep a fallback plan to deepseek-v4-flash or another vision model.

Key Takeaways

• deepseek-v4-flash-vision-exp is an experimental multimodal model for image understanding — not an image generator.
• It supports 1M context, 384K output, and three API formats with flexible image input methods.
• Official pricing is the same tier as V4 Flash; check our model pricing page for current rates through this gateway.
• As an experimental route, it requires validation, rate limits, and a rollback plan before replacing production defaults.