gpt-oss-120b vs Mercury 2.5
| Signal | gpt-oss-120b | Delta | Mercury 2.5 |
|---|---|---|---|
Capabilities | 67 | -- | |
Benchmarks | 60 | +1 | |
Pricing | 99 | 0 | |
Context window size | 81 | -5 | |
Recency | 58 | -42 | |
Output Capacity | 77 | -- | |
| Overall Result | 1 wins | of 6 | 3 wins |
Score History
61.6
current score
gpt-oss-120b
right now
61.2
current score
gpt-oss-120b
OpenAI
Mercury 2.5
Inception
Mercury 2.5 saves you $33.50/month
That's $402.00/year compared to gpt-oss-120b at your current usage level of 100K calls/month.
| Metric | gpt-oss-120b | Mercury 2.5 | Winner |
|---|---|---|---|
| Overall Score | 62 | 61 | gpt-oss-120b |
| Rank | #209 | #211 | gpt-oss-120b |
| Quality Rank | #209 | #211 | gpt-oss-120b |
| Adoption Rank | #209 | #211 | gpt-oss-120b |
| Parameters | 120B | -- | -- |
| Context Window | 131K | 260K | Mercury 2.5 |
| Pricing | $0.15/$0.60/M | $0.04/$0.15/M | -- |
| Signal Scores | |||
| Capabilities | 67 | 67 | gpt-oss-120b |
| Benchmarks | 60 | 60 | gpt-oss-120b |
| Pricing | 99 | 100 | Mercury 2.5 |
| Context window size | 81 | 86 | Mercury 2.5 |
| Recency | 58 | 100 | Mercury 2.5 |
| Output Capacity | 77 | 77 | gpt-oss-120b |
Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.
Scores 62/100 (rank #209), placing it in the top 28% of all 290 models tracked.
Scores 61/100 (rank #211), placing it in the top 28% of all 290 models tracked.
With only a 0-point gap, these models are in the same performance tier. The practical difference in output quality is minimal - your choice should depend on pricing, latency requirements, and specific feature needs.
Choose gpt-oss-120b when you need:
- Step-by-step reasoning and chain-of-thought problem solving
- Self-hosted deployments where you need full control over the model
Choose Mercury 2.5 when you need:
- High-volume production workloads where API costs must be minimized
- Processing long documents or large codebases (260K token context)
- Step-by-step reasoning and chain-of-thought problem solving
Mercury 2.5 offers 75% better value per quality point. At 1M tokens/day, you'd spend $2.85/month with Mercury 2.5 vs $11.25/month with gpt-oss-120b - a $8.40 monthly difference.
Both models have comparable response speeds. For most applications, the latency difference is negligible.
When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.
Code generation & review
Based on overall model capabilities and architecture for coding tasks like generating functions, debugging, and refactoring
Customer support chatbot
Suitable for user-facing chat with competitive response times. Mercury 2.5 also offers lower per-token costs for high-volume support
Long document analysis
Larger context window (260K tokens) can process longer documents, contracts, and research papers in a single pass
Batch data extraction
Lower output pricing ($0.15/M) reduces costs when processing thousands of records daily
Creative writing & content
Higher overall composite score (62/100) correlates with better nuance, coherence, and style in long-form content
gpt-oss-120b and Mercury 2.5 are extremely close in overall performance (only 0.3999999999999986 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.
By Use Case
Best for Quality
gpt-oss-120b
Marginally better benchmark scores; both are excellent
Best for Cost
Mercury 2.5
75% lower pricing; better value at scale
Best for Reliability
gpt-oss-120b
Higher uptime and faster response speeds
Best for Prototyping
gpt-oss-120b
Stronger community support and better developer experience
Best for Production
gpt-oss-120b
Wider enterprise adoption and proven at scale
by OpenAI
- Choose for Quality - Marginally better benchmark scores; both are excellent
- Choose for Reliability - Higher uptime and faster response speeds
- Choose for Prototyping - Stronger community support and better developer experience
- Choose for Production - Wider enterprise adoption and proven at scale
| Capability | gpt-oss-120b | Mercury 2.5 |
|---|---|---|
| Vision (Image Input) | ||
| Function Calling | ||
| Streaming | ||
| JSON Mode | ||
| Reasoning | ||
| Web Search | ||
| Image Output |
gpt-oss-120b
OpenAI
Mercury 2.5
Inception
Mercury 2.5 saves you $0.7380/month
That's 75% cheaper than gpt-oss-120b at 1,000 tokens/request and 100 requests/day.
Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.
| Parameter | gpt-oss-120b | Mercury 2.5 |
|---|---|---|
| Context Window | 131K | 260K |
| Max Output Tokens | 65,536 | 65,536 |
| Open Source | Yes | No |
| Created | Aug 5, 2025 | Sep 8, 2026 |