GPT-5.5 vs DeepSeek V4 Flash

GPT-5.5 from OpenAI and DeepSeek V4 Flash from DeepSeek are shown side by side so you can compare pricing, model IDs, context and output limits, modalities, tool use, release details, and benchmark results where data is available.

Overall Recommendation

GPT-5.5 is the clear capability default, with materially higher Intelligence and Coding indexes plus image and PDF input. Choose DeepSeek V4 Flash for high-volume text processing at the lowest listed token price.

Recommendation based on GPT-5.5 (xhigh) vs DeepSeek V4 Flash (Reasoning, Max Effort).

Comparison Highlights

GPT-5.5OpenAI
DeepSeek V4 FlashDeepSeek
Best For
Professional codingresearchdocument-heavy work
High-throughputcost-sensitive long-context workloads
How To Read ItUse-case synthesis from model capabilities and positioning.
Workload Fit
CodingAnalysisKnowledge work
ThroughputLow costLong context
How To Read ItThe workloads each model is most directly shaped for.
Input
$5/M
$0.4286/MEdge
How To Read ItLower is better when prompts or retrieval payloads are large.
Output
$30/M
$1.2857/MEdge
How To Read ItLower is better for reasoning-heavy or long-generation traffic.
Context length
1.1M
1M
How To Read ItHigher is better for repositories, retrieval packs, and transcripts.
Input modalities
Image, PDF, TextEdge
Text
How To Read ItBroader input support reduces the need for separate vision or video models.

Model Selection Guide

GPT-5.5OpenAI

Choose GPT-5.5 When

  • A 54.8 Intelligence Index and 59.1 Coding Index in TokenHub’s xhigh profile
  • $5 input and $30 output per million tokens, with $0.50 cached input
  • A 1.05M context window, 128K maximum output, and text, image, and PDF input
DeepSeek V4 FlashDeepSeek

Choose DeepSeek V4 Flash When

  • The lowest listed price: $0.15 input and $0.30 output per million tokens
  • A 40.3 Intelligence Index and 38.7 Coding Index in TokenHub’s max-effort profile
  • A 1M context window and 384K maximum output for high-volume text workloads

Basic Information

GPT-5.5OpenAI
DeepSeek V4 FlashDeepSeek

Name

GPT-5.5GPT-5.5

Model id

GPT-5.5gpt-5.5

Intro

GPT-5.5GPT-5.5 is described by OpenAI as a smarter frontier model for coding, research, data analysis, and professional knowledge work. The official launch messaging emphasizes higher capability, better speed than previous difficult-work models, and strong performance on tasks involving documents and structured analysis. Its description should focus on broad professional intelligence rather than a single niche.

Author

GPT-5.5OpenAI

Released date

GPT-5.52026-04-23

Context length

GPT-5.51.1M

Max output tokens

GPT-5.5128K

Name

DeepSeek V4 FlashDeepSeek V4 Flash

Model id

DeepSeek V4 Flashdeepseek-v4-flash

Intro

DeepSeek V4 FlashDeepSeek V4 Flash keeps the V4 family’s 1M-token context window but uses a lighter MoE configuration, commonly described as 284B total parameters with 13B activated parameters. The emphasis is throughput: fast inference, lower cost per call, and production workloads that still need long-context handling. It is the better fit when the task volume is high and the workload benefits from V4-style long-context architecture without always requiring the deepest reasoning tier.

Author

DeepSeek V4 FlashDeepSeek

Released date

DeepSeek V4 Flash2026-04-24

Context length

DeepSeek V4 Flash1M

Max output tokens

DeepSeek V4 Flash384K

Pricing

GPT-5.5OpenAI
DeepSeek V4 FlashDeepSeek

Input

GPT-5.5$5/M

Output

GPT-5.5$30/M

Cached input

GPT-5.5$0.5/M

Input

DeepSeek V4 Flash$0.4286/M

Output

DeepSeek V4 Flash$1.2857/M

Cached input

DeepSeek V4 Flash$0.0143/M

Capabilities

GPT-5.5OpenAI
DeepSeek V4 FlashDeepSeek

Reasoning

GPT-5.5

Knowledge

GPT-5.52025-12-01

Attachment

GPT-5.5

Input modalities

GPT-5.5Image, PDF, Text

Output modalities

GPT-5.5Text

Temperature

GPT-5.5

Tool use

GPT-5.5

Reasoning

DeepSeek V4 Flash

Knowledge

DeepSeek V4 Flash2025-05-01

Attachment

DeepSeek V4 Flash

Input modalities

DeepSeek V4 FlashText

Output modalities

DeepSeek V4 FlashText

Temperature

DeepSeek V4 Flash

Tool use

DeepSeek V4 Flash

Benchmark

GPT-5.5OpenAI
DeepSeek V4 FlashDeepSeek

Intelligence

wins54.8

Coding

wins59.1

Intelligence

40.3

Coding

38.7

Knowledge & Reasoning

GPQA

wins93.5%

HLE

wins44.3%

GPQA

89.4%

HLE

32.1%

Coding

SciCode

wins56.1%

Terminal-Bench Hard

wins60.6%

SciCode

44.9%

Terminal-Bench Hard

35.6%

Instruction Following & Agent Tasks

IFBench

75.9%

AA-LCR

wins74.3%

Tau2

93.9%

IFBench

wins79.2%

AA-LCR

63%

Tau2

wins95.0%

FAQ

Which model is better, GPT-5.5 or DeepSeek V4 Flash?

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GPT-5.5 and DeepSeek V4 Flash should be compared by workload. This page places price, context, output limits, capabilities, and benchmark data side by side. It is also relevant to: deepseek vs chatgpt, chatgpt vs deepseek, deepseek vs chatgpt comparison, deepseek ai vs chatgpt, deepseek vs openai, openai vs deepseek.

Is DeepSeek V4 Flash cheaper than GPT-5.5?

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Use the pricing rows above to compare input, output, and cached input prices for GPT-5.5 and DeepSeek V4 Flash.

Which model supports a longer context length?

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GPT-5.5 lists 1.1M context length, while DeepSeek V4 Flash lists 1M.

Can I access both models through TokenHub?

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If both models are available in the TokenHub catalog, you can route requests to GPT-5.5 and DeepSeek V4 Flash through the TokenHub API.