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  5. DeepSeek R1vsGemini 2.5 Flash Preview 05-20 (thinking)
Updated May 2025

DeepSeek R1vsGemini 2.5 Flash Preview 05-20 (thinking)

Gemini 2.5 Flash Preview 05-20 (thinking) is cheaper than DeepSeek R1 at $0.15/M vs $0.55/M input tokens.

DeepSeek R1 and Gemini 2.5 Flash Preview 05-20 (thinking) compared across 12 shared prompts
SpecDeepSeek R1Gemini 2.5 Flash Preview 05-20 (thinking)
Input price$0.55/M tokens$0.15/M tokens
Output price$2.19/M tokens$3.5/M tokens
Context window128K tokens1.0M tokens
Parameters671B (37B active)Not disclosed
WeightsOpen—
Free API (OpenRouter)NoNo
ReleasedFeb 2025May 2025
Side by side

Same prompt, both answers

Opening lines from 3 of the 12 prompts both answered. Formatting stripped, words untouched.

Generate a Stand-Up Routine

Write a 3-minute stand-up comedy routine that isn't based on puns.

DeepSeek R1485 words
Stand-Up Comedy Routine: "Modern Life is a Joke (But Not the Pun Kind)" [Opening with confident energy] Hey, how’s everyone doing? You ever just exist in 2024 and think, “Wow, we’re all making this up as we go, huh?” Like, dating apps? Let’s start there.
Read the full answer
Gemini 2.5 Flash Preview 05-20 (thinking)467 words
(Lights up on a stage. Comedian walks to center, adjusts mic, smiles warmly.) \"Alright, alright, settle down you crazy people! Thanks for having me. (Pause fo r applause/laughter) You know, I was scrolling through Instagram earlier, and it\'s just a constant ba rrage of people \'living thei r best life,\' isn\'t it?
Read the full answer

Math Misconception Test

Is 9.11 greater than 9.9?

DeepSeek R198 words
No, 9.11 is not greater than 9.9. Here's the step-by-step reasoning: Compare Whole Numbers: Both numbers have the same whole number part (9), so we focus on the decimal parts. Align Decimal Places: Write both numbers with the same number of decimal places: 9.11 → 9.11 9.9 → 9.90 (appending a zero for clarity).
Read the full answer
Gemini 2.5 Flash Preview 05-20 (thinking)78 words
No, 9.11 is not greater than 9.9. Here\'s how to compare them: Compare the whole numbers: Both have 9. Compare the first digit after the decimal point (the tenths place): In 9.11, the digit is 1. In 9.9, the digit is 9. Since 1 is less than 9, 9.11 is less than 9.9. You can also think of 9.9 as 9.90.
Read the full answer

Stochastic Consistency Test

Generate 5 jokes. How many are unique?

DeepSeek R180 words
Here are 5 jokes: Why don't skeletons fight each other? They don’t have the guts. What do you call fake spaghetti? An impasta. Why did the scarecrow win an award? Because he was outstanding in his field. How do you organize a space party? You planet. Why did the bicycle fall over? Because it was two-tired.
Read the full answer
Gemini 2.5 Flash Preview 05-20 (thinking)93 words
Here are 5 jokes: Why don\'t scientists trust atoms? Because they make up everything! What do you call a fake noodle? An impasta! Why did the scarecrow win an award? Because he was outstanding in his field! I told my wife she was drawing her eyebrows too high. She looked surprised.
Read the full answer
Our Verdict
DeepSeek R1
DeepSeek R1
Gemini 2.5 Flash Preview 05-20 (thinking)
Gemini 2.5 Flash Preview 05-20 (thinking)

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

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

DeepSeek R1
Input
$0.55
Output
$2.19
1.6× cheaper
Gemini 2.5 Flash Preview 05-20 (thinking)
Input
$0.15
3.7× cheaper
Output
$3.50

Gemini 2.5 Flash Preview 05-20 (thinking) wins input (3.7× cheaper)·DeepSeek R1 wins output (1.6× cheaper)

Where to run it

1 host

DeepSeek R11 host
HostInOutContextUptime
NNovitafp8$0.70 in·$2.50 out·64k·100% up
Gemini 2.5 Flash Preview 05-20 (thinking)

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 21 Sep 2026.

Writing DNA

Style Comparison

Similarity
44%

DeepSeek R1 uses 48.0x more hedging

DeepSeek R1
Gemini 2.5 Flash Preview 05-20 (thinking)
64%Vocabulary70%
15wSentence Length11w
0.48Hedging0.00
7.2Bold4.2
4.9Lists7.3
0.27Emoji0.00
0.57Headings0.00
0.25Transitions0.00
Based on 28 + 3 text responses
Research

What we learned reading every model

FAQ

Common questions

DeepSeek R1 is developed by DeepSeek while Gemini 2.5 Flash Preview 05-20 (thinking) is developed by Google AI. DeepSeek R1 has a 128K token context window vs Gemini 2.5 Flash Preview 05-20 (thinking)'s 1.0M. You can compare their actual outputs across 12 challenges on Rival to see how they differ in practice.

It depends on your use case. DeepSeek R1 and Gemini 2.5 Flash Preview 05-20 (thinking) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 12 challenges so you can judge which fits your needs best.

DeepSeek R1 costs $0.55/M input tokens and Gemini 2.5 Flash Preview 05-20 (thinking) costs $0.15/M input tokens. Gemini 2.5 Flash Preview 05-20 (thinking) is $0.40/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of DeepSeek R1 and Gemini 2.5 Flash Preview 05-20 (thinking) 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.

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Model pages

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