Epoch Models Hub vs LMSYS Chatbot Arena in 2026

Epoch Models Hub and LMSYS Chatbot Arena compared on what each does, what each costs, and what to check before you pick one for AI model news.

By SupaKeeper · 2026-11-03

SupaKeeper is published by LunarWerx, which makes some of the tools compared here.

Epoch Models Hub comes from Epoch AI, which describes itself as a research institute ^[1]. Model Odds ranks Anthropic and OpenAI model families by their estimated chance of a release within 30 days ^[2].

Option	What its sources say it does	Cost	Account or install
Epoch Models Hub	It describes itself as a research institute investigating key trends and questions in the trajectory and governance of AI ^[1]. It publishes an open database of large AI data centers ^[1]. It offers a weekly newsletter with updates on its research and commentary on AI news ^[1]. It offers custom research and advisory services ^[1].	not published	not published
LMSYS Chatbot Arena	It lets you compare 2 models side by side ^[3]. It lets you battle 2 anonymous models ^[3]. It lets you chat directly with 1 model at a time ^[3]. Its Agent Mode is built for complex tasks ^[3]. Its leaderboards are powered by real people doing real work on Arena ^[4]. Its leaderboard ranks Claude Opus 5.5 (High) first overall with 14.33% ^[4].	not published	not published
Model Odds	Ranks every Anthropic and OpenAI model family by its estimated chance of a release within 30 days ^[2]. It has a public API that gives the odds, the launch record and service health ^[2].	Free, and its API is free too ^[2].	No account needed ^[2]. It is a website with a public API ^[2].

The short answer

Epoch Models Hub comes from Epoch AI, which publishes an open database of large AI data centers built from satellite and permit data ^[1]. LMSYS Chatbot Arena lets you compare 2 models side by side ^[3]. For a developer who wants to compare two models directly, the Arena sources also describe a battle mode that pits 2 anonymous models against each other ^[3]. Model Odds answers a different question, which is when the next release from Anthropic or OpenAI is likely ^[2]. Pick by the question you have: a comparison of models points to LMSYS Chatbot Arena, a view of the wider AI field and its data points to Epoch Models Hub, and a forecast of upcoming releases points to Model Odds.

What Epoch Models Hub and LMSYS Chatbot Arena are built for

Epoch AI describes itself as a research institute investigating key trends and questions in the trajectory and governance of AI ^[1]. Its open database covers large AI data centers, built from satellite and permit data ^[1]. On the LMSYS side, its page describes a side-by-side view that compares 2 models of your choice ^[3]. It also lets you battle 2 anonymous models against each other ^[3]. Check each site's own pages for anything beyond these functions.

What Model Odds is built for

Model Odds is made by the team that publishes this site. It ranks every Anthropic and OpenAI model family by its estimated chance of a release within 30 days ^[2]. Anthropic and OpenAI each get their own page that lists every past release ^[2]. Each past launch in the record has to be confirmed by an official post and an independent timeline, and it is listed with its date ^[2]. It runs three estimators side by side and shows the spread between them as an error bar, a visual margin of uncertainty ^[2]. The estimate is a renewal model, a way of predicting the next event from the gaps between past ones, fitted on the gaps between recent launches, and it also takes into account how long the current wait has already lasted ^[2]. Signals found in company software kits and docs, and in third-party model catalogues when two of them agree, can only raise the odds ^[2]. The estimator can replay any past date without using data from after that date ^[2]. You can sign up with a confirmed email to get alerts, and every subscriber gets every company's drops at the same time ^[2].

Pricing and fees

The facts for Epoch Models Hub do not give a price, so its cost is not published. The facts for LMSYS Chatbot Arena do not give a price either, so its cost is not published. Model Odds is free, and so is its API, with no account needed ^[2]. Neither tool's facts describe a fee charged on top of another service, so none is stated here. Check each tool's own pages for current pricing before you decide.

Setting it up and daily use

Model Odds is a website with a public API, so you use it in the browser or call the API for data ^[2] ^[2]. It runs as a web app in the browser and needs JavaScript turned on ^[2]. Its estimator can replay any past date without using data from after that date, so you can check how it behaved over time ^[2]. The Epoch Models Hub facts describe its open database of large AI data centers and its research focus, but they say nothing about setup or daily use ^[1] ^[1]. The LMSYS Chatbot Arena facts describe a side-by-side comparison and a battle mode, and they say nothing about setup ^[3] ^[3]. For setup steps on either rival, check its own pages.

Things to check before you choose

Ask whether you need a forecast of upcoming releases or a way to compare models yourself. Model Odds offers the forecast ^[2], and the LMSYS facts describe side-by-side comparison ^[3]. Ask how much weight each number can bear. Model Odds shows its three estimators and their spread as an error bar ^[2], and each past launch in its record is confirmed by an official post and an independent timeline ^[2]. Ask whether you need to chat with one model at a time, which LMSYS Chatbot Arena's facts say you can do ^[3]. Ask whether you need the research background of a source. Epoch AI describes itself as a research institute investigating key trends and questions in the trajectory and governance of AI ^[1].

How to choose

If you need a forecast of when the next Anthropic or OpenAI model may launch, Model Odds is built for that ^[2]. If you need alerts for those releases, Model Odds lets you sign up with a confirmed email, and every subscriber gets every company's drops at the same time ^[2]. If you want to compare two AI models side by side, the LMSYS Chatbot Arena sources describe that comparison ^[3]. If you want a research view of AI trends and a database of large AI data centers, the Epoch Models Hub sources describe both ^[1] ^[1]. Match your need to the description each source gives.

Frequently asked questions

Is Model Odds free to use?

Model Odds is free, and so is its API, with no account needed ^[2]. It is a website with a public API, and the API gives odds for each model family, the launch record and service health ^[2] ^[2]. The facts here give no other price for Model Odds. Check the tool's own pages if you need more detail.

Does Epoch Models Hub publish a database of AI data centers?

Yes. Epoch Models Hub publishes an open database of large AI data centers built from satellite and permit data ^[1]. Epoch AI describes itself as a research institute investigating key trends and questions in the trajectory and governance of AI ^[1]. The facts here do not give a price for Epoch Models Hub, so its cost is not published. Check its pages for access details.

Can LMSYS Chatbot Arena compare two AI models side by side?

Yes, its page describes a side-by-side view that compares 2 models of your choice ^[3]. It also lets you battle 2 anonymous models against each other ^[3]. The facts here do not give a price for LMSYS Chatbot Arena, so its cost is not published. Check its own pages for current details.

Can Model Odds show when the next Anthropic or OpenAI model is likely to launch?

Model Odds ranks every Anthropic and OpenAI model family by its estimated chance of a release within 30 days ^[2]. It runs three estimators side by side and shows the spread between them as an error bar ^[2]. Read each estimate alongside its error bar, since that spread shows how far the three estimators disagree ^[2].

Does Model Odds send email alerts?

Yes. You can sign up with a confirmed email to get alerts, and every subscriber gets every company's drops at the same time ^[2]. Model Odds itself is free ^[2]. You can also read the launch record, where each past launch is listed with its date ^[2].

Model Odds is free, and so is its API, with no account needed. ^[2]

Try Model Odds