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Gemini 3.8 Flash vs Mercury 2.5

Updated October 23, 2026. Rank says Gemini 3.8 Flash is ahead. Price, access, and your workload can each overturn that. Public scores include evidence status and uncertainty.

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Decision reading

Gemini 3.8 Flash has the higher public point estimate, 69.01 versus 33.38. Their conditional score ranges do not overlap. These ranges do not establish rank confidence. 1 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

Model A
Google logo

Google

69.01/100

Supported · Public rank #21

90% interval 63.4–74.6

Model B
Inception logo

Inception

33.38/100

Estimated · Public rank #166

Conditional range 19.0–47.7

Shared results
1
Gemini 3.8 Flash only
33
Mercury 2.5 only
5
Like-for-like categories
2 / 8
Supported: Gemini 3.8 Flash · Estimated: Mercury 2.5. Conditional ranges do not establish rank confidence.How the comparison works

Which one for your work

Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.

  • Agentic work

    Tool use, computer use, and multi-step task completion

    Gemini 3.8 Flash

    Gemini 3.8 Flash has the higher public agentic point estimate, 66.2 to 12, with Supported evidence for both models. The conditional ranges do not establish rank confidence.

    Confidence: limited
  • Long documents

    Prompts that approach the documented context limit

    Gemini 3.8 Flash

    Gemini 3.8 Flash has the larger documented context window.

    Confidence: documented
  • Chat turn cost

    1K fresh input + 500 output tokens

    Mercury 2.5

    Mercury 2.5 has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
Show secondary and unsupported calls
  • Cache-heavy agent loop cost

    200K cached + 20K fresh input + 10K output tokens

    Mercury 2.5

    Mercury 2.5 has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
  • Repository review cost

    50K fresh input + 3K output tokens

    Mercury 2.5

    Mercury 2.5 has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
  • Coding work

    Code generation, repair, and software-engineering tasks

    Not enough matched evidence

    Mercury 2.5 is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like.

    Confidence: limited

Which one for a specific job

Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.

The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.

60.8Gemini 3.8 Flash16.1Mercury 2.5

Directional only · BenchAlign v5.8

Gemini 3.8 Flash has the higher coding point estimate. Conditional score ranges do not establish rank confidence.

Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.

Same basis rules as the category table below

What is actually comparable

Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.

1 category rests on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.

Shape of the matched evidence

Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.

A shared-evidence shape is not available.

BenchLM does not draw a radar or infer missing axes when the matched evidence is too sparse.

Category results, on a stated basis

Each row shows the public-lane category score for both models: the BenchAlign v5.8 lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.

Agentic

Like-for-like
Gemini 3.8 Flash
66.2
Supported · #16/132
Mercury 2.5
12.0
Supported · #123/132
Basis
BenchAlign v5.8 lane · 9 vs 3 public rows
Reading
Gemini 3.8 Flash leads

Knowledge

Like-for-like
Gemini 3.8 Flash
72.8
Supported · #13/187
Mercury 2.5
33.8
Supported · #139/187
Basis
BenchAlign v5.8 lane · 6 vs 1 public rows
Reading
Gemini 3.8 Flash leads

Coding

Directional only
Gemini 3.8 Flash
60.8
Supported · #19/153
Mercury 2.5
16.1
Estimated · #133/153
Basis
BenchAlign v5.8 lane · 8 vs 1 public rows
Reading
Directional only

Reasoning

Not comparable
Gemini 3.8 Flash
74.3
#14/27
Mercury 2.5
71.7
Unranked · 2 rankable rows
Basis
Provisional lane · 2 vs 0 weighted rows
Reading
Not comparable

Multimodal

Not comparable
Gemini 3.8 Flash
88.2
#7/56
Mercury 2.5
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Multilingual

Not comparable
Gemini 3.8 Flash
Not ranked
Mercury 2.5
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Instruction following

Not comparable
Gemini 3.8 Flash
Not ranked
Mercury 2.5
81.1
#60/153
Basis
Provisional lane · 0 vs 1 weighted rows
Reading
Not comparable

Math

Not comparable
Gemini 3.8 Flash
69.7
Unranked · 2 rankable rows
Mercury 2.5
Not ranked
Basis
Provisional lane · 2 vs 0 weighted rows
Reading
Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.8) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.

Supported evidence per lane · bars run 0–100Methodology

What each workload costs

Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.

Chat turn

1K fresh input + 500 output tokens

Gemini 3.8 Flash
$0.00262
Fits in one request
Mercury 2.5
$0.00012
Fits in one request

Mercury 2.5 has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

Gemini 3.8 Flash
$0.04875
Fits in one request
Mercury 2.5
$0.00245
Fits in one request

Mercury 2.5 has the lower modeled cost

Costs use the listed standard API rates.

Cache-heavy agent loop

200K cached + 20K fresh input + 10K output tokens

Gemini 3.8 Flash
$0.0675
Fits in one request
Mercury 2.5
$0.0031
Fits in one request

Mercury 2.5 has the lower modeled cost

Costs use the listed standard API rates.

Cached input falls back to the list input rate only where a cached rate is unpublished

Specification differences

Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.

Reasoning profile

Gemini 3.8 Flash

Reasoning

Mercury 2.5

Reasoning

Weight access

Gemini 3.8 Flash

Proprietary

Mercury 2.5

Proprietary

License

Gemini 3.8 Flash

Proprietary

Mercury 2.5

Proprietary

Release date

Gemini 3.8 Flash

2026-09-02

Mercury 2.5

2026-09-08

If you already use one of these models

Deployment change
The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
Quality signal
Gemini 3.8 Flash has the higher public point estimate, 69.01 versus 33.38. Their conditional score ranges do not overlap. These ranges do not establish rank confidence.
Workload cost
Repository review: $0.04875 vs $0.00245. Cache-heavy agent loop: $0.0675 vs $0.0031.
Context tradeoff
Gemini 3.8 Flash has the larger documented window (1M).
Run the same representative tasks against both endpoints before changing production traffic.

Questions

Which is better, Gemini 3.8 Flash or Mercury 2.5?

Gemini 3.8 Flash has the higher public point estimate, 69.01 versus 33.38. Their conditional score ranges do not overlap. These ranges do not establish rank confidence. The page therefore keeps the decision tied to the specific documented workload.

Which is better for coding, Gemini 3.8 Flash or Mercury 2.5?

Gemini 3.8 Flash scores higher for coding on the public lane, 60.8 to 16.1. Mercury 2.5 is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like. BenchLM does not name a winner for coding from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which is better for agentic tasks, Gemini 3.8 Flash or Mercury 2.5?

Gemini 3.8 Flash has the higher public agentic tasks point estimate, 66.2 to 12, with Supported evidence for both models. The conditional ranges do not establish rank confidence.

Which costs less, Gemini 3.8 Flash or Mercury 2.5?

For the stated presets, chat costs $0.00263 on Gemini 3.8 Flash and $0.00012 on Mercury 2.5; repository review costs $0.04875 and $0.00245; the cache-heavy agent loop costs $0.0675 and $0.0031. Costs use the listed standard API rates.

Which has the larger context window, Gemini 3.8 Flash or Mercury 2.5?

Gemini 3.8 Flash has the larger documented context window: 1M, compared with 260K.

Benchmark evidence

The full public result ledger is available for audit without forcing a wide desktop table onto a phone.

Browse raw public benchmark evidence39 rows

Agentic

  • Finance Agent v2

    Gemini 3.8 Flash61.4%
    Source
    Mercury 2.5—

    Not directly comparable

  • Terminal-Bench 2.1

    Gemini 3.8 Flash89.4%
    Source
    Mercury 2.5—

    Not directly comparable

  • Terminal-Bench 4.0

    Gemini 3.8 Flash19.10%
    Source
    Mercury 2.5—

    Not directly comparable

  • OSWorld 2.0

    Gemini 3.8 Flash59.0%
    Source
    Mercury 2.5—

    Not directly comparable

  • Terminal-Bench 2.1 (Vals)

    Gemini 3.8 Flash81.3%
    Source
    Mercury 2.534.5%
    Source

    Gemini 3.8 Flash leads this result

  • ApprenticeBench

    Gemini 3.8 Flash24%
    Source
    Mercury 2.5—

    Not directly comparable

  • Hermes Index

    Gemini 3.8 Flash38.1%
    Source
    Mercury 2.5—

    Not directly comparable

  • Hermes Bench

    Gemini 3.8 Flash62.2%
    Source
    Mercury 2.5—

    Not directly comparable

  • MazeBench

    Gemini 3.8 Flash4%
    Source
    Mercury 2.5—

    Not directly comparable

  • τ³-bench results

    Gemini 3.8 Flash—
    Mercury 2.596.0%
    Source

    Not directly comparable

  • DeepSearchQA

    Gemini 3.8 Flash—
    Mercury 2.534.0%
    Source

    Not directly comparable

Coding

  • DeepSWE

    Gemini 3.8 Flash73.8%
    Source
    Mercury 2.5—

    Not directly comparable

  • Terminal-Bench 2.1

    Gemini 3.8 Flash89.4%
    Source
    Mercury 2.5—

    Not directly comparable

  • CursorBench 3.2

    Gemini 3.8 Flash69.2%
    Source
    Mercury 2.5—

    Not directly comparable

  • LiveCodeBench (Vals)

    Gemini 3.8 Flash89.5%
    Source
    Mercury 2.5—

    Not directly comparable

  • SWE-bench (Vals)

    Gemini 3.8 Flash80.0%
    Source
    Mercury 2.5—

    Not directly comparable

  • FrontierSWE v2

    Gemini 3.8 Flash19.6%
    Source
    Mercury 2.5—

    Not directly comparable

  • CursorBench 4.0

    Gemini 3.8 Flash39.6%
    Source
    Mercury 2.5—

    Not directly comparable

  • Bug Hunt Bench

    Gemini 3.8 Flash18.0 fixes
    Source
    Mercury 2.5—

    Not directly comparable

  • SciCode

    Gemini 3.8 Flash—
    Mercury 2.538%
    Source

    Not directly comparable

Reasoning

  • ARC-AGI-1

    Gemini 3.8 Flash98.50%
    Source
    Mercury 2.5—

    Not directly comparable

  • ARC-AGI-2

    Gemini 3.8 Flash89.2%
    Source
    Mercury 2.5—

    Not directly comparable

  • ARC-AGI-3

    Gemini 3.8 Flash10.4%
    Source
    Mercury 2.5—

    Not directly comparable

  • ARC-AGI-3 Provider Adapter

    Gemini 3.8 Flash35.00%
    Source
    Mercury 2.5—

    Not directly comparable

Multimodal

  • ExtractBench (LlamaIndex)

    Gemini 3.8 Flash80.71%
    Source
    Mercury 2.5—

    Not directly comparable

  • ParseBench

    Gemini 3.8 Flash72.08%
    Source
    Mercury 2.5—

    Not directly comparable

  • CharXiv w/o tools

    Gemini 3.8 Flash86.2%
    Source
    Mercury 2.5—

    Not directly comparable

  • LVBench

    Gemini 3.8 Flash87.1%
    Source
    Mercury 2.5—

    Not directly comparable

Knowledge

  • HLE-Verified

    Gemini 3.8 Flash54.9%
    Source
    Mercury 2.5—

    Not directly comparable

  • LABBench2

    Gemini 3.8 Flash86.2%
    Source
    Mercury 2.5—

    Not directly comparable

  • BioMysteryBench (human-solvable)

    Gemini 3.8 Flash88.8%
    Source
    Mercury 2.5—

    Not directly comparable

  • BioMysteryBench (human-difficult)

    Gemini 3.8 Flash56.5%
    Source
    Mercury 2.5—

    Not directly comparable

  • GPQA Diamond (Vals)

    Gemini 3.8 Flash94.4%
    Source
    Mercury 2.5—

    Not directly comparable

  • MMLU-Pro (Vals)

    Gemini 3.8 Flash90.2%
    Source
    Mercury 2.5—

    Not directly comparable

  • GPQA-D

    Gemini 3.8 Flash—
    Mercury 2.579.0%
    Source

    Not directly comparable

Instruction following

  • Gray Swan IPI (15 attempts)

    Gemini 3.8 Flash5.5%
    Source
    Mercury 2.5—

    Not directly comparable

  • IFBench

    Gemini 3.8 Flash—
    Mercury 2.577%
    Source

    Not directly comparable

Math

  • FrontierMath v2 (Tiers 1-3)

    Gemini 3.8 Flash68.421%
    Source
    Mercury 2.5—

    Not directly comparable

  • FrontierMath v2 (Tier 4)

    Gemini 3.8 Flash21.951%
    Source
    Mercury 2.5—

    Not directly comparable

39 public results · 1 shared

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Last updated October 23, 2026