Side-by-side comparison · AI Assistants & LLMs

Duck.ai vs LMArena

Everything that matters when choosing between them, in one place: our rating, what each can do, what they cost, and the trade-offs.

Best overall

Duck.ai

4.0

From $9.99/mo or $99.99/yr

Details Visit

LMArena

3.8

Free to start

Details Visit

Comparing 2 tools. Add one more if you like.

At a glance

Duck.ai4.0

Best overallEasiest to use

Pick it if: Anyone who wants quick AI help without an account or a record of what they asked.

LMArena3.8

Best value

Pick it if: Anyone choosing between AI tools, and people who want to know which model is leading right now.

Duck.ai scores highest overall, but LMArena gives you more for your money. Which one is right comes down to what you value most.

Overview

Attribute	Duck.ai	LMArena
In one line	DuckDuckGo's private AI chat: no account, no stored prompts, free to use.	Free site where you compare AI models side by side and see which ones people rate best.
Pricing model	Freemium	Free
Starting price	$9.99/mo or $99.99/yr	Free
Free plan	Yes	Yes
Works with Claude Code	No	No

Rating breakdown

Our scores out of 5. The higher bar in each row is highlighted.

Attribute	Duck.ai	LMArena
Overall rating	4.0Winner	3.8
Ease of useHow quickly someone non-technical gets value from it.	4.5	3.5
FeaturesHow completely it covers its own job, and how well the pieces fit together.	3.0	4.0
Output qualityHow good the results are before you fix them.	3.5	3.5
Value for moneyWhat you get for the price, including the free plan.	4.5	5.0
Speed & reliabilityHow fast it is and how often it falls over.	4.5	3.0

Feature comparison

A tick means it does this today. A dash means we haven't checked.

Attribute	Duck.ai	LMArena
Access & platform
Free plan	Yes	Yes
Mobile app	Yes	No
Desktop app	Yes	No
Browser extension	Yes	No
API access	No	No
Teams & business
Team workspace	No	No
Enterprise plan or SSO	No	No
Connects to other apps	No	No
Open source or self-hosted	No	No
AI abilities
Works with your files	Yes	Yes
Understands images	Yes	Yes
Makes images	Yes	Yes
Makes video	No	Yes
Writes code	Yes	Yes
Runs agents or automations	No	No
Learns your brand or style	No	No
Works in many languages	Yes	Yes
Capabilities score	9/ 17	7/ 17

Pricing

Plans as listed on each vendor's site when we last checked. Confirm before you buy.

Attribute	Duck.ai	LMArena
Plans	FreeOur pick Free Quick private questions with no sign-up.	FreeOur pick Free Everyone.
	Plus $9.99/mo or $99.99/yr Regular users who also want a VPN.
	Pro $19.99/mo or $199.99/yr People who want the top models privately.
Which plan to pick	Stay on Free unless you also want a VPN. Plus is good value if you'd pay for a VPN anyway. Pro is $19.99, the same as ChatGPT Plus or Claude Pro, so only pick it if anonymity matters more to you than features.	There's nothing to buy. Use it free, and pay for whichever assistant comes out best for your work.

Key features

Attribute	Duck.ai	LMArena
Standout features	No account needed Anonymised prompts Choice of models Voice chat and images Local chat history Built into the browser	Battle mode Side by side Direct chat Leaderboards Agent mode Early access

Pros and cons

Attribute	Duck.ai	LMArena
Pros	No account, and prompts are anonymised and not used for training Free access to models from OpenAI, Anthropic and Mistral in one place Fast, clean and easy for anyone to use Paid plans bundle a VPN and identity protection	Free access to the leading models, often before release Blind voting makes it easy to judge models on output alone Leaderboards cover text, code, images, video and agents Real people's preferences are harder to game than lab benchmarks
Cons	Free models are the small versions, so answers trail paid ChatGPT or Claude No projects, connectors or spreadsheet uploads, and PDFs are capped at 15 to 50 pages Usage limits aren't published as numbers Privacy rests on DuckDuckGo's contracts with the AI companies, and some users report chat sync errors between devices	Rankings favour answers that look good, and labs have been caught testing private versions to climb the board Conversations are collected and partly shared with model makers, so keep private work out Frequent "something went wrong" errors, captchas, logouts and models removed without notice Direct chat is being narrowed, with newer models only available in random battles The company now sells evaluations to the labs it ranks, which raises questions about neutrality

Who each one is for

Attribute	Duck.ai	LMArena
Best for	Quick private questions Using AI without signing up A shared or work computer Voice chat and simple image making	Choosing between AI models with your own prompts Checking which model leads after a launch Trying top models for free Comparing image and video models
You'll find it used by	Privacy-minded professionals DuckDuckGo users Casual AI users Students	AI enthusiasts Developers Product teams Journalists

Questions people ask

Which is better, Duck.ai or LMArena?

Duck.ai scores highest overall in our ratings (Duck.ai 4.0/5 and LMArena 3.8/5). Duck.ai is best for quick private questions and Using AI without signing up. LMArena is best for choosing between AI models with your own prompts and checking which model leads after a launch.

Which is cheaper, Duck.ai or LMArena?

Duck.ai: There's a free plan, and paid plans start at $9.99/mo or $99.99/yr. LMArena: It's free to use.

Which is easier to use, Duck.ai or LMArena?

Duck.ai rates highest for ease of use in our scores. Anyone who wants quick AI help without an account or a record of what they asked.

Ratings are our own, from using each tool, across ease of use, features, output quality, value for money, speed & reliability.

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