Everything about Mercury 2.5
Mercury 2.5 in numbers: price per token, context window, independent benchmark scores and comparable models, based on public data checked on October 22, 2026.
Data as of October 22, 2026
Key figures
| Developer | Inception |
|---|---|
| Released | September 8, 2026 |
| Knowledge cutoff | November 1, 2025 |
| Context window | 260,000 tokens (≈ 390 pages) |
| Maximum output | 65,536 tokens |
| Input price | $0.20 per million tokens (developer's price) |
| Output price | $0.75 per million tokens |
| Open weights | No |
| Reasoning mode | Yes |
| Tool calling | Yes |
| Structured output (JSON) | Yes |
| Accepted inputs | text |
| Providers offering it | 6 |
Mercury 2.5 at a glance
Released on September 8, 2026, Mercury 2.5 is one of the 2 Inception models tracked on this site. Its weights are not published, so it only runs remotely, through the Inception API or partner hosts (6 listed on models.dev). It has a reasoning mode: it can "think" before answering, which helps with multi-step problems but uses more tokens, and therefore more money. It is a very recent release.
We file it under budget models (24 models in this category on the site).
What it costs
Mercury 2.5 costs $0.20 per million input tokens and $0.75 per million output tokens (developer's price, checked on October 22, 2026).
In practice, an agent task that reads 20,000 tokens and writes 2,000 costs about $0.006, or $5.5 for 1,000 such tasks.
That is 1.5 times cheaper than the median output price of budget models ($1.13).
Tokens read back from cache cost $0.02 per million, which helps an agent that keeps resending the same context.
To estimate your own budget, use the agent cost calculator.
Benchmark results
As of October 22, 2026, Epoch AI publishes no score for Mercury 2.5 on our basket's benchmarks. To place it, rely on its specifications and price, then test it on your own cases.
What it can do
Its context window reaches 260,000 tokens, roughly 390 pages of text at 500 words per page: enough for a long report or several contracts at once. A single answer can run to 65,536 tokens.
It accepts as input: text. Its knowledge stops at November 1, 2025: beyond that, it needs web search or your documents.
It can call tools (functions, APIs) and return structured JSON output, which makes it a possible foundation for an AI agent.
When to choose it
Given its category, Mercury 2.5 is mainly aimed at high volumes where every cent counts: sorting, information extraction, summaries, simple assistants.
Before adopting it, test it on your own examples: benchmarks measure standard tasks, not your job.
What could replace it?
In the same category, the models closest to Mercury 2.5 are:
- Seed 2.0 Lite (ByteDance Seed, $0.76 per million output tokens)
- Codestral 25.08 (Mistral AI, $0.90 per million output tokens)
- MiniMax-M3.1-Flash (MiniMax, $0.60 per million output tokens)
- GPT-6 Luna (OpenAI, index 80.3)
Similar models
- Seed 2.0 Lite · ByteDance Seed
- Codestral 25.08 · Mistral AI
- MiniMax-M3.1-Flash · MiniMax
- GPT-6 Luna · OpenAI · index 80.3
Other Inception models
- Mercury 3 · October 16, 2026
Frequently asked questions
How much does Mercury 2.5 cost?
As of October 22, 2026, Mercury 2.5 costs $0.20 per million input tokens and $0.75 per million output tokens (developer's price). A task that reads 20,000 tokens and writes 2,000 costs about $0.006.
What is the context window of Mercury 2.5?
260,000 tokens, roughly 390 pages of text. An answer can reach 65,536 tokens.
Is Mercury 2.5 open source?
No. It is a closed Inception model, available only through an API.
When was Mercury 2.5 released?
Mercury 2.5 was released on September 8, 2026, according to models.dev.
Can you build an agent with Mercury 2.5?
Yes: it can call tools and return structured JSON, the two basic building blocks of an agent.
Data sources
- Models.dev — Model data: models.dev (open-source project)
- OpenRouter — Market prices cross-checked with OpenRouter
Data as of October 22, 2026
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