ZMIME
Comparison · 3 models · Updated Nov 2, 2026

Gemini 2.5 Flash Preview 05-20 vs GPT OSS 120B vs DeepSeek R1 0528

Gemini 2.5 Flash Preview 05-20 comes out ahead, 67 to 58 and 53 on our weighted score, though GPT OSS 120B is 2.3× cheaper per token.

  1. Our pick

    Google

    Gemini 2.5 Flash Preview 05-20

    Released May 20, 2025

    67/100
    • ECI141.5
    • Price$0.146 / $1.96
    • Context1.05M
    Full specs Remove Gemini 2.5 Flash Preview 05-20

  2. OpenAI

    GPT OSS 120B

    Released Aug 5, 2025

    58/100
    • ECI139.8
    • Price$0.15 / $0.60
    • Context131K
    Full specs Remove GPT OSS 120B

  3. DeepSeek

    DeepSeek R1 0528

    Released May 28, 2025

    53/100
    • ECI141.2
    • Price$0.512 / $2.19
    • Context164K
    Full specs Remove DeepSeek R1 0528
01 — Verdict

Gemini 2.5 Flash Preview 05-20 is our pick

Gemini 2.5 Flash Preview 05-20 is the better all-round choice, scoring 67/100 against GPT OSS 120B (58) and DeepSeek R1 0528 (53). It leads on inputs & features and context window. GPT OSS 120B wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGemini 2.5 Flash Preview 05-20Capabilities Index (ECI): Gemini 2.5 Flash Preview 05-20 141.5 · DeepSeek R1 0528 141.2 · GPT OSS 120B 139.8
  • Lowest priceGPT OSS 120BGPT OSS 120B $0.263 · Gemini 2.5 Flash Preview 05-20 $0.60 · DeepSeek R1 0528 $0.932 per 1M tokens (3:1 blend)
  • Longest contextGemini 2.5 Flash Preview 05-20Gemini 2.5 Flash Preview 05-20 1,048,576 · DeepSeek R1 0528 163,840 · GPT OSS 120B 131,072 tokens
  • Widest inputsGemini 2.5 Flash Preview 05-20Gemini 2.5 Flash Preview 05-20: Text, Images, PDFs, Audio, Video · GPT OSS 120B: Text · DeepSeek R1 0528: Text
  • Self-hostingGPT OSS 120B and DeepSeek R1 0528Publishes downloadable weights (MIT)
How the score is built
MeasureWeightGemini 2.5 Flash Preview 05-20GPT OSS 120BDeepSeek R1 0528
CapabilityCapabilities Index (ECI)50%666466
Price25%587449
Inputs & features15%903535
Context window10%612528
Overall100%67/10058/10053/100
02 — Side by side

Every spec in one table

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

Gemini 2.5 Flash Preview 05-20 vs GPT OSS 120B vs DeepSeek R1 0528 specifications side by side
SpecificationGemini 2.5 Flash Preview 05-20GoogleGPT OSS 120BOpenAIDeepSeek R1 0528DeepSeek
Capability
Capabilities Index (ECI)141.5 (best)139.8141.2
ECI rank#106 of 165 (best)#114 of 165#108 of 165
GPQA DiamondGraduate-level science questions—75.8%76.3% (best)
OTIS Mock AIME 2024–2025Competition mathematics70.8%88.9% (best)66.4%
Price per million tokens
Input$0.146 (best)$0.15$0.512
Output$1.96$0.60 (best)$2.19
Cached input———
Blended (3:1)$0.60$0.263 (best)$0.932
Long-context rateSame rateSame rateSame rate
Price sourceMedian of 2 providersMedian of 65 providersMedian of 16 providers
Limits
Context window1,048,576 tokens (best)131,072 tokens163,840 tokens
Max output65,536 tokens (best)32,768 tokens32,768 tokens
Inputs and features
TextYesYesYes
ImagesYesNoNo
PDFsYesNoNo
AudioYesNoNo
VideoYesNoNo
ReasoningYesYesYes
Tool callingYesYesYes
Structured outputNoNoNo
Availability
WeightsProprietaryOpenOpenMIT
API model ID———
API providers267 (best)16
ReleasedMay 20, 2025Aug 5, 2025May 28, 2025
Knowledge cutoffJan 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.

  • Gemini 2.5 Flash Preview 05-20$5.39
  • GPT OSS 120B$2.70
  • DeepSeek R1 0528$9.50
04 — Questions

Which should you choose?

Which is better: Gemini 2.5 Flash Preview 05-20, GPT OSS 120B or DeepSeek R1 0528?

Gemini 2.5 Flash Preview 05-20 is the better all-round choice, scoring 67/100 against GPT OSS 120B (58) and DeepSeek R1 0528 (53). It leads on inputs & features and context window. GPT OSS 120B wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Gemini 2.5 Flash Preview 05-20, GPT OSS 120B or DeepSeek R1 0528?

GPT OSS 120B is cheaper at $0.15 input / $0.60 output per million tokens (median across 65 API providers). Gemini 2.5 Flash Preview 05-20 costs $0.146 input / $1.96 output per million tokens (median across 2 API providers); 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 $0.263 per million tokens for GPT OSS 120B versus $0.60 for Gemini 2.5 Flash Preview 05-20 (2.3× as much) and $0.932 for DeepSeek R1 0528 (3.6× as much).

Which scores higher on benchmarks?

Gemini 2.5 Flash Preview 05-20 scores higher on the Capabilities Index (ECI): Gemini 2.5 Flash Preview 05-20 141.5 (#106 of 165), DeepSeek R1 0528 141.2 (#108 of 165) and GPT OSS 120B 139.8 (#114 of 165). The confidence ranges of the top two overlap (139.3–142.9 vs 139.0–142.9), so treat the gap as small. On individual benchmarks: OTIS Mock AIME 2024–2025 — GPT OSS 120B 88.9%, Gemini 2.5 Flash Preview 05-20 70.8%, DeepSeek R1 0528 66.4%.

Which is better for coding?

There are no published SWE-bench Verified results for Gemini 2.5 Flash Preview 05-20, GPT OSS 120B and DeepSeek R1 0528 yet, so there is no like-for-like coding score. On overall capability, Gemini 2.5 Flash Preview 05-20 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 Preview 05-20 has the largest context window at 1,048,576 tokens, against 163,840 for DeepSeek R1 0528 and 131,072 for GPT OSS 120B. Maximum output per response: Gemini 2.5 Flash Preview 05-20 up to 65,536, GPT OSS 120B up to 32,768, DeepSeek R1 0528 up to 32,768 tokens.

Which can read images, PDFs, audio or video?

Gemini 2.5 Flash Preview 05-20 accepts text, images, PDFs, audio and video; GPT OSS 120B accepts text; DeepSeek R1 0528 accepts text. Gemini 2.5 Flash Preview 05-20 handles the widest range of inputs.

Are any of these open source?

GPT OSS 120B and DeepSeek R1 0528 publishes its weights (MIT) and can be self-hosted; Gemini 2.5 Flash Preview 05-20 is proprietary.

Which is newer?

GPT OSS 120B is the newest, released Aug 5, 2025. DeepSeek R1 0528 came out May 28, 2025; Gemini 2.5 Flash Preview 05-20 came out May 20, 2025. Knowledge cutoff: Gemini 2.5 Flash Preview 05-20 Jan 2025, GPT OSS 120B 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.

05 — Keep comparing

Related comparisons