Inception Mercury 2
Hacker ApprovedThe most recommended of 3 diffusion language models
Recommended for very fast responses at low cost for agentic subtasks, autocomplete and quick iteration. Critics say it trails frontier models on accuracy and reliability.
Recommended for very fast responses at low cost for agentic subtasks, autocomplete and quick iteration. Critics say it trails frontier models on accuracy and reliability.
92 people gave an opinion
- recommend it
- 64
- criticize it
- 28
- approval share
- 70%
Recommended in 6 of 13 months
- November 2025: recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: recommended
- March 2026: not recommended
- April 2026: recommended
- May 2026: not recommended
- June 2026: recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 64 people recommend itNeeds 10 or more, met.
- 2.3 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 6 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Very fast token speed
“The main differentiator is latency — it’s ~5× faster at comparable quality.”
Comment from 25 Feb 2026 in “Mercury 2: The fastest reasoning LLM, powered by diffusion” “it's still incredibly fast compared to what I'm used to with other models”
Comment from 19 Oct 2026 in “Mercury 3: Diffusion at scale” “The virtually instantaneous responses of Inception's Mercury models”
Comment from 18 Apr 2026 in “I'm Coding by Hand” - Comment from 8 Sep 2026 in “Mercury 2.5”
- Comment from 19 Oct 2026 in “Mercury 3: Diffusion at scale”
- Comment from 19 Oct 2026 in “Mercury 3: Diffusion at scale”
- Comment from 20 Feb 2026 in “The path to ubiquitous AI (17k tokens/sec)”
- Comment from 19 Oct 2026 in “Mercury 3: Diffusion at scale”
Useful for subagents and subtasks
“Even pretty dumb models are useful for running subtasks (especially at this sort of speed).”
Comment from 9 Sep 2026 in “Mercury 2.5” “this model and previous are halfway decent and you can do diffusion sub-agents”
Comment from 9 Sep 2026 in “Mercury 2.5” “early testing has found the model to be great for coding subagents”
Comment from 19 Oct 2026 in “Mercury 3: Diffusion at scale” - Comment from 24 Sep 2026 in “Mercury 2.5 LLM hits 770 tokens per second”
- Comment from 25 Feb 2026 in “Mercury 2: The fastest reasoning LLM, powered by diffusion”
Cheap per request
“It's much less impressive-looking than any of the above, but it cost less than 1/20th of a cent”
Comment from 2 Sep 2026 in “Gemini 3.8 Flash and 3.8 Flash Cyber” “gets roflstomped by Mercury 3 at both cost and performance at similar TPS speed”
Comment from 25 Oct 2026 in “Cerebras Deploys Trillion-Parameter AI Models” “Having a cheap 1,000 tok/s option for coding work is a dream”
Comment from 19 Oct 2026 in “Mercury 3: Diffusion at scale” Clear gains over earlier versions
“with thinking off, it was considerably better than Mercury 2 and generally good in fact, not very sloppy”
Comment from 9 Sep 2026 in “Mercury 2.5” “Seems like a definite improvement over 2.5 though in my testing”
Comment from 19 Oct 2026 in “Mercury 3: Diffusion at scale”
What people warn about
Each mark is one comment
Trails frontier models on quality
“I can see some promise with diffusion LLMs, but getting them comparable to the frontier is going to require a ton of work”
Comment from 25 Feb 2026 in “Mercury 2: The fastest reasoning LLM, powered by diffusion” “Output quality, tool calling reliability and task adherence tend to be far more reliable across all three over Mercury 2”
Comment from 14 Apr 2026 in “Introspective Diffusion Language Models” “it is light years behind frontier models. Speed is great, but wrong is much worse than slow”
Comment from 9 Sep 2026 in “Mercury 2.5” - Comment from 23 Sep 2026 in “Mercury 2.5 LLM hits 770 tokens per second”
- Comment from 24 Sep 2026 in “Mercury 2.5 LLM hits 770 tokens per second”
Wrong, incorrect or looping output
“it generates incorrect information, and it doesn't fix it when later in the text it realizes that it is incorrect”
Comment from 25 Feb 2026 in “Mercury 2: The fastest reasoning LLM, powered by diffusion” “I had a very odd interaction somewhat similar to how weak transformer models get into a loop”
Comment from 25 Feb 2026 in “Mercury 2: The fastest reasoning LLM, powered by diffusion” “it is light years behind frontier models. Speed is great, but wrong is much worse than slow”
Comment from 9 Sep 2026 in “Mercury 2.5” Not as fast as advertised
“It's not really all that fast, for most things it's full seconds or at least a significant portion of a second.”
Comment from 20 Oct 2026 in “Mercury 3: Diffusion at scale” “It seems like the chat demo is really suffering from the effect of everything going into a queue.”
Comment from 25 Feb 2026 in “Mercury 2: The fastest reasoning LLM, powered by diffusion” Expensive without input caching
“the lack of an input cache discount makes it prohibitively expensive for most use cases that aren't one-shot prompts”
Comment from 24 Sep 2026 in “Mercury 2.5 LLM hits 770 tokens per second” “Pricing at $0.25 and $0.75 already puts its cost well above reasonably reputable inference providers”
Comment from 23 Sep 2026 in “Mercury 2.5 LLM hits 770 tokens per second”
Other diffusion language models people recommend
The two most recommended other diffusion language models, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Inception Mercury 2This page | 64 | 28 | 70% | 6 | — | Approved |
| DiffusionGemma | 15 | 7 | 68% | 5 | — | Approved |
| Inception Labs | 5 | 1 | 83% | 4 | — | — |
What people said
40 of the 115 comments that mention it, newest first. Each links to the original comment.
“gets roflstomped by Mercury 3 at both cost and performance at similar TPS speed”
“It's not really all that fast, for most things it's full seconds or at least a significant portion of a second.”
“it's still incredibly fast compared to what I'm used to with other models”
“love these guys. instead of spending time on something akin to those creepy "dots"... they ship actual improvements to speed”
“It's really fast and works really well in my initial tests.”
“Those are some far better .svgs than I got last Mercury 2.5. Unfortunately no real improvement under iteration”
“early testing has found the model to be great for coding subagents”
“Customers are already using Mercury 3 for browser use agents, interactive education, real-time search agents, customer support, and more.”
“I'm going to start using this instead of Haiku/GPT-Luna for tasks that require speed.”
“I created a pelican worked wonderfully, better than old haiku model or even sonnet models”
“Having a cheap 1,000 tok/s option for coding work is a dream”
“Seems like a definite improvement over 2.5 though in my testing”
“Outperforms GPT-6 Luna and Claude Haiku 5.5 across a range of benchmarks at matched reasoning effort.”
“for small, transactional tasks it is quite strong and fast”
“Mercury 2.5 is below average in intelligence, but well priced when comparing to other models of similar price.”
“the lack of an input cache discount makes it prohibitively expensive for most use cases that aren't one-shot prompts”
“Pricing at $0.25 and $0.75 already puts its cost well above reasonably reputable inference providers”
“The speed means absolutely nothing when it is finishing almost dead last when compared to the frontier AI companies.”
“Mercury 2.5 is truly groundbreaking, giving it a try is highly recommended.”
“it is light years behind frontier models. Speed is great, but wrong is much worse than slow”
“with thinking off, it was considerably better than Mercury 2 and generally good in fact, not very sloppy”
“Even pretty dumb models are useful for running subtasks (especially at this sort of speed).”
“this model and previous are halfway decent and you can do diffusion sub-agents”
“I like the text output on logical and historical content that I sampled so far”
“having a model run at 1100tps goes a long a way to alleviate that”
“mercury-2 was pretty good”
“It's much less impressive-looking than any of the above, but it cost less than 1/20th of a cent”
“Mercury-2 is amazing. I am using it frequently as the arbiter in llm-consortium”
“The virtually instantaneous responses of Inception's Mercury models”
“Output quality, tool calling reliability and task adherence tend to be far more reliable across all three over Mercury 2”
“it made some interactions nearly frictionless, very close to how old school autocomplete/T9/autocorrect works”
“So Mercury 2 scores significantly higher on speed (96 vs 62), while being comparable on cost efficiency”
“it generates incorrect information, and it doesn't fix it when later in the text it realizes that it is incorrect”
“I had a very odd interaction somewhat similar to how weak transformer models get into a loop”
“We see Mercury 2 as enabling very fast iteration for agentic tasks.”
“The main differentiator is latency — it’s ~5× faster at comparable quality.”
“I can see some promise with diffusion LLMs, but getting them comparable to the frontier is going to require a ton of work”
“It seems like the chat demo is really suffering from the effect of everything going into a queue.”
“What excites me most about these new 4figure/second token models is that you can essentially do multi-shot prompting”
“The speed is still impressive when playing aroun with it sometimes”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.