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Comparison · 2 models · Updated Oct 4, 2026

Mercury 2 vs Mercury 2.5

Mercury 2.5 comes out ahead, 71 to 53 on our weighted score, and it is the cheaper option too.

  1. Inception

    Mercury 2

    Released Feb 24, 2026

    53/100
    • ECI—
    • Price$0.25 / $0.75
    • Context128K
  2. Our pick

    Inception

    Mercury 2.5

    Released Sep 8, 2026

    71/100
    • ECI—
    • Price$0.04 / $0.15
    • Context260K
  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Mercury 2.5 is our pick

Mercury 2.5 is the better all-round choice, scoring 71/100 against Mercury 2 (53). It leads on price and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceMercury 2.5Mercury 2.5 $0.068 · Mercury 2 $0.375 per 1M tokens (3:1 blend)
  • Longest contextMercury 2.5Mercury 2.5 260,000 · Mercury 2 128,000 tokens
  • Widest inputsSame inputsMercury 2: Text · Mercury 2.5: Text
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightMercury 2Mercury 2.5
Price50%70100
Inputs & features30%4545
Context window20%2436
Overall100%53/10071/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

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

Mercury 2 vs Mercury 2.5 specifications side by side
SpecificationMercury 2InceptionMercury 2.5Inception
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.25$0.04 (best)
Output$0.75$0.15 (best)
Cached input$0.025$0.004 (best)
Blended (3:1)$0.375$0.068 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Inception APIOfficial Inception API
Limits
Context window128,000 tokens260,000 tokens (best)
Max output50,000 tokens65,536 tokens (best)
Inputs and features
TextYesYes
ImagesNoNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · highYeslow · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDmercury-2mercury-2.5
API providers11
ReleasedFeb 24, 2026Sep 8, 2026
Knowledge cutoffJan 1, 2025Nov 1, 2025
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.

  • Mercury 2$4.00
  • Mercury 2.5$0.70
04 — Questions

Which should you choose?

Which is better: Mercury 2 or Mercury 2.5?

Mercury 2.5 is the better all-round choice, scoring 71/100 against Mercury 2 (53). It leads on price and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, Mercury 2 or Mercury 2.5?

Mercury 2.5 is cheaper at $0.04 input / $0.15 output per million tokens (official Inception API price). Mercury 2 costs $0.25 input / $0.75 output per million tokens (official Inception API price). At a typical mix of three input tokens to one output token, that is $0.068 per million tokens for Mercury 2.5 versus $0.375 for Mercury 2 (5.6× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Mercury 2 has not been scored yet and Mercury 2.5 has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Mercury 2 and Mercury 2.5 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

Mercury 2.5 has the largest context window at 260,000 tokens, against 128,000 for Mercury 2. Maximum output per response: Mercury 2 up to 50,000, Mercury 2.5 up to 65,536 tokens.

Which can read images, PDFs, audio or video?

Mercury 2 accepts text; Mercury 2.5 accepts text. They handle the same number of input types.

Are any of these open source?

No. Mercury 2 and Mercury 2.5 are proprietary and only available through APIs and apps.

Which is newer?

Mercury 2.5 is the newest, released Sep 8, 2026. Mercury 2 came out Feb 24, 2026. Knowledge cutoff: Mercury 2 Jan 1, 2025, Mercury 2.5 Nov 1, 2025.

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 Oct 4, 2026.