Model Comparison

GPT-5.4 vs Mercury 2

GPT-5.4 significantly outperforms across most benchmarks. Mercury 2 is 15.0x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

GPT-5.4 outperforms in 1 benchmarks (GPQA), while Mercury 2 is better at 0 benchmarks.

GPT-5.4 significantly outperforms across most benchmarks.

Mon Apr 20 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Mercury 2 costs less

For input processing, GPT-5.4 ($2.50/1M tokens) is 10.0x more expensive than Mercury 2 ($0.25/1M tokens).

For output processing, GPT-5.4 ($15.00/1M tokens) is 20.0x more expensive than Mercury 2 ($0.75/1M tokens).

In conclusion, GPT-5.4 is more expensive than Mercury 2.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Apr 20 2026 • llm-stats.com
OpenAI
GPT-5.4
Input tokens$2.50
Output tokens$15.00
Best providerOpenAI
Inception
Mercury 2
Input tokens$0.25
Output tokens$0.75
Best providerInception
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.4 accepts 1,000,000 input tokens compared to Mercury 2's 128,000 tokens. GPT-5.4 can generate longer responses up to 128,000 tokens, while Mercury 2 is limited to 8,192 tokens.

OpenAI
GPT-5.4
Input1,000,000 tokens
Output128,000 tokens
Inception
Mercury 2
Input128,000 tokens
Output8,192 tokens
Mon Apr 20 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.4 supports multimodal inputs, whereas Mercury 2 does not.

GPT-5.4 can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5.4

Text
Images
Audio
Video

Mercury 2

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

GPT-5.4

Proprietary

Closed source

Mercury 2

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.4 was released on 2026-03-05, while Mercury 2 was released on 2026-02-24.

GPT-5.4 is 0 month newer than Mercury 2.

GPT-5.4

Mar 5, 2026

1 months ago

1w newer
Mercury 2

Feb 24, 2026

1 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

GPT-5.4 is available from OpenAI. Mercury 2 is available from Inception.

GPT-5.4

openai logo
OpenAI
Input Price:Input: $2.50/1MOutput Price:Output: $15.00/1M

Mercury 2

inception logo
Inception
Input Price:Input: $0.25/1MOutput Price:Output: $0.75/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (1,000,000 tokens)
Supports multimodal inputs
Higher GPQA score (92.8% vs 74.0%)
Inception
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-5.4
Inception
Mercury 2

FAQ

Common questions about GPT-5.4 vs Mercury 2

GPT-5.4 significantly outperforms across most benchmarks. GPT-5.4 is made by OpenAI and Mercury 2 is made by Inception. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
GPT-5.4 scores Tau2 Telecom: 98.9%, ARC-AGI: 93.7%, Graphwalks BFS <128k: 93.0%, GPQA: 92.8%, Graphwalks parents <128k: 89.8%. Mercury 2 scores AIME 2025: 91.1%, GPQA: 74.0%, IFBench: 71.0%, LiveCodeBench: 67.0%, Tau2 Airline: 53.0%.
Mercury 2 is 10.0x cheaper for input tokens. GPT-5.4 costs $2.50/M input and $15.00/M output via openai. Mercury 2 costs $0.25/M input and $0.75/M output via inception.
GPT-5.4 supports 1.0M tokens and Mercury 2 supports 128K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (1.0M vs 128K), input pricing ($2.50 vs $0.25/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.
GPT-5.4 is developed by OpenAI and Mercury 2 is developed by Inception.