What is the difference between DeepSeek V4.1 Flash and GPT-4.5?

DeepSeek V4.1 Flash is developed by DeepSeek while GPT-4.5 is developed by OpenAI. DeepSeek V4.1 Flash has a 1.0M token context window vs GPT-4.5's 128K. You can compare their actual outputs across 1 challenges on Rival to see how they differ in practice.

Which is better, DeepSeek V4.1 Flash or GPT-4.5?

It depends on your use case. DeepSeek V4.1 Flash and GPT-4.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 1 challenges so you can judge which fits your needs best.

How much does DeepSeek V4.1 Flash cost compared to GPT-4.5?

DeepSeek V4.1 Flash costs $0.15/M input tokens and GPT-4.5 costs $75/M input tokens. DeepSeek V4.1 Flash is $74.85/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare DeepSeek V4.1 Flash and GPT-4.5 on Rival?

This page shows a side-by-side comparison of DeepSeek V4.1 Flash and GPT-4.5 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Updated Sep 2026

DeepSeek V4.1 FlashvsGPT-4.5

DeepSeek V4.1 Flash is cheaper than GPT-4.5 at $0.15/M vs $75/M input tokens.

DeepSeek V4.1 Flash and GPT-4.5 compared across 1 shared prompts
Spec	DeepSeek V4.1 Flash	GPT-4.5
Input price	$0.15/M tokens	$75/M tokens
Output price	$0.6/M tokens	$150/M tokens
Context window	1.0M tokens	128K tokens
Weights	Open	—
Free API (OpenRouter)	No	No
Released	Sep 2026	Feb 2025

Our Verdict

DeepSeek V4.1 Flash

GPT-4.5

Not enough votes to call it. On the specs, nothing separates them.

DeepSeek V4.1 Flash costs 250x less per token.

Too close to call

API pricing

Cost per 1M tokens

DeepSeek V4.1 Flash

Input

$0.15

500× cheaper

Output

$0.60

250× cheaper

GPT-4.5

Input

$75.00

Output

$150.00

DeepSeek V4.1 Flash is cheaper on both: 500× input, 250× output.

Where to run it

23 hosts, cheapest first

DeepSeek V4.1 Flash23 hosts

HostInOutContextUptime

OpenInferencefp4$0.10 in$0.50 out1M99.5% up Wafer$0.12 in$0.60 out1M99.7% up Relacefp4$0.12 in$0.52 out1M99.9% up Morph$0.13 in$0.51 out1M98.4% up Sail Researchfp4$0.13 in$0.75 out1M99.9% up DeepInfrafp8$0.14 in$0.42 out1M99.7% up

17 more hosts

StreamLakefp8$0.15 in$0.60 out1M99.5% up CoreWeavefp8$0.20 in$0.65 out1M99.2% up Fireworks$0.22 in$0.66 out1M98.8% up Phala$0.28 in$1.10 out1M99.4% up GMI Cloudfp8$0.28 in$1.14 out1M99.6% up Novitafp8$0.28 in$1.14 out1M100% up Alibaba Cloud$0.30 in$1.20 out1M99.9% up AtlasCloudfp8$0.30 in$1.20 out1M99.7% up Basetenfp8$0.30 in$1.20 out1M99.4% up DeepSeek$0.30 in$1.20 out1M100% up DigitalOcean$0.30 in$1.20 out1M97.9% up Makora$0.30 in$1.20 out1M98.9% up Modal$0.30 in$1.20 out1M99.8% up SiliconFlowfp8$0.30 in$1.20 out1M99.8% up Together$0.30 in$1.20 out1M99.9% up Venicefp8$0.38 in$1.50 out1M96.7% up Parasailfp8degraded$0.30 in$1.20 out1M93% up

GPT-4.5

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 23 Sep 2026.

Research

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Cost per 1M tokens

23 hosts, cheapest first

What we learned reading every model

Common questions

What is the difference between DeepSeek V4.1 Flash and GPT-4.5?

Which is better, DeepSeek V4.1 Flash or GPT-4.5?

How much does DeepSeek V4.1 Flash cost compared to GPT-4.5?

How can I compare DeepSeek V4.1 Flash and GPT-4.5 on Rival?

More comparisons

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Cost per 1M tokens

23 hosts, cheapest first

What we learned reading every model

Common questions

What is the difference between DeepSeek V4.1 Flash and GPT-4.5?

Which is better, DeepSeek V4.1 Flash or GPT-4.5?

How much does DeepSeek V4.1 Flash cost compared to GPT-4.5?

How can I compare DeepSeek V4.1 Flash and GPT-4.5 on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages