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Comparison · 3 models · Updated Nov 2, 2026

DeepSeek R1 0528 vs Gemini 2.5 Flash vs GPT OSS 20B

Gemini 2.5 Flash comes out ahead, 66 to 61 and 53 on our weighted score, though GPT OSS 20B is 7.4× cheaper per token.

  1. DeepSeek

    DeepSeek R1 0528

    Released May 28, 2025

    53/100
    • ECI141.2
    • Price$0.512 / $2.19
    • Context164K
  2. Our pick

    Google

    Gemini 2.5 Flash

    Released Jun 17, 2025

    66/100
    • ECI140.6
    • Price$0.30 / $2.50
    • Context1.05M
  3. OpenAI

    GPT OSS 20B

    Released Aug 5, 2025

    61/100
    • ECI137.8
    • Price$0.07 / $0.25
    • Context131K
01 — Verdict

Gemini 2.5 Flash is our pick

Gemini 2.5 Flash is the better all-round choice, scoring 66/100 against GPT OSS 20B (61) and DeepSeek R1 0528 (53). It leads on inputs & features and context window. GPT OSS 20B wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityDeepSeek R1 0528Capabilities Index (ECI): DeepSeek R1 0528 141.2 · Gemini 2.5 Flash 140.6 · GPT OSS 20B 137.8
  • Lowest priceGPT OSS 20BGPT OSS 20B $0.115 · Gemini 2.5 Flash $0.85 · DeepSeek R1 0528 $0.932 per 1M tokens (3:1 blend)
  • Longest contextGemini 2.5 FlashGemini 2.5 Flash 1,048,576 · DeepSeek R1 0528 163,840 · GPT OSS 20B 131,072 tokens
  • Widest inputsGemini 2.5 FlashDeepSeek R1 0528: Text · Gemini 2.5 Flash: Text, Images, PDFs, Audio, Video · GPT OSS 20B: Text
  • Self-hostingDeepSeek R1 0528 and GPT OSS 20BPublishes downloadable weights (MIT)
How the score is built
MeasureWeightDeepSeek R1 0528Gemini 2.5 FlashGPT OSS 20B
CapabilityCapabilities Index (ECI)50%666561
Price25%495190
Inputs & features15%3510035
Context window10%286125
Overall100%53/10066/10061/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

DeepSeek R1 0528 vs Gemini 2.5 Flash vs GPT OSS 20B specifications side by side
SpecificationDeepSeek R1 0528DeepSeekGemini 2.5 FlashGoogleGPT OSS 20BOpenAI
Capability
Capabilities Index (ECI)141.2 (best)140.6137.8
ECI rank#108 of 165 (best)#110 of 165#122 of 165
GPQA DiamondGraduate-level science questions76.3% (best)—60.8%
OTIS Mock AIME 2024–2025Competition mathematics66.4% (best)—65.3%
Price per million tokens
Input$0.512$0.30$0.07 (best)
Output$2.19$2.50$0.25 (best)
Cached input—$0.03—
Blended (3:1)$0.932$0.85$0.115 (best)
Long-context rateSame rateSame rateSame rate
Price sourceMedian of 16 providersOfficial Google APIMedian of 37 providers
Limits
Context window163,840 tokens1,048,576 tokens (best)131,072 tokens
Max output32,768 tokens65,536 tokens (best)32,768 tokens
Inputs and features
TextYesYesYes
ImagesNoYesNo
PDFsNoYesNo
AudioNoYesNo
VideoNoYesNo
ReasoningYesYesYes
Tool callingYesYesYes
Structured outputNoYesNo
Availability
WeightsOpenMITProprietaryOpen
API model ID—gemini-2.5-flash—
API providers163241 (best)
ReleasedMay 28, 2025Jun 17, 2025Aug 5, 2025
Knowledge cutoff—Jan 2025Jun 2024
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • DeepSeek R1 0528$9.50
  • Gemini 2.5 Flash$8.00
  • GPT OSS 20B$1.20
04 — Questions

Which should you choose?

Which is better: DeepSeek R1 0528, Gemini 2.5 Flash or GPT OSS 20B?

Gemini 2.5 Flash is the better all-round choice, scoring 66/100 against GPT OSS 20B (61) and DeepSeek R1 0528 (53). It leads on inputs & features and context window. GPT OSS 20B wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, DeepSeek R1 0528, Gemini 2.5 Flash or GPT OSS 20B?

GPT OSS 20B is cheaper at $0.07 input / $0.25 output per million tokens (median across 37 API providers). Gemini 2.5 Flash costs $0.30 input / $2.50 output per million tokens (official Google API price); DeepSeek R1 0528 costs $0.512 input / $2.19 output per million tokens (median across 16 API providers). At a typical mix of three input tokens to one output token, that is $0.115 per million tokens for GPT OSS 20B versus $0.85 for Gemini 2.5 Flash (7.4× as much) and $0.932 for DeepSeek R1 0528 (8.1× as much).

Which scores higher on benchmarks?

DeepSeek R1 0528 scores higher on the Capabilities Index (ECI): DeepSeek R1 0528 141.2 (#108 of 165), Gemini 2.5 Flash 140.6 (#110 of 165) and GPT OSS 20B 137.8 (#122 of 165). The confidence ranges of the top two overlap (139.0–142.9 vs 138.4–142.1), so treat the gap as small.

Which is better for coding?

There are no published SWE-bench Verified results for DeepSeek R1 0528, Gemini 2.5 Flash and GPT OSS 20B yet, so there is no like-for-like coding score. On overall capability, DeepSeek R1 0528 leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Which has the bigger context window?

Gemini 2.5 Flash has the largest context window at 1,048,576 tokens, against 163,840 for DeepSeek R1 0528 and 131,072 for GPT OSS 20B. Maximum output per response: DeepSeek R1 0528 up to 32,768, Gemini 2.5 Flash up to 65,536, GPT OSS 20B up to 32,768 tokens.

Which can read images, PDFs, audio or video?

DeepSeek R1 0528 accepts text; Gemini 2.5 Flash accepts text, images, PDFs, audio and video; GPT OSS 20B accepts text. Gemini 2.5 Flash handles the widest range of inputs.

Are any of these open source?

DeepSeek R1 0528 and GPT OSS 20B publishes its weights (MIT) and can be self-hosted; Gemini 2.5 Flash is proprietary.

Which is newer?

GPT OSS 20B is the newest, released Aug 5, 2025. Gemini 2.5 Flash came out Jun 17, 2025; DeepSeek R1 0528 came out May 28, 2025. Knowledge cutoff: Gemini 2.5 Flash Jan 2025, GPT OSS 20B Jun 2024.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.