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Side-by-side comparison · AI Assistants & LLMs

DeepSeek vs Duck.ai vs Perplexity

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

DeepSeek

3.8

From Pay per use

Duck.ai

4.0

From $9.99/mo or $99.99/yr

Best overall

Perplexity

4.2

From $17/mo

Comparing 3 tools, the maximum.

At a glance

Best value

Pick it if: Anyone who wants a strong reasoning assistant for free, and developers watching their API costs.

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

Best overall

Pick it if: Anyone who researches as part of their job and is sick of having ten tabs open.

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

Overview

AttributeDeepSeekDuck.aiPerplexity
In one lineA free Chinese assistant that's strong at maths, logic and code.DuckDuckGo's private AI chat: no account, no stored prompts, free to use.Ask a question and get a short answer from the web, with links to every source.
Pricing modelFreeFreemiumFreemium
Starting pricePay per use$9.99/mo or $99.99/yr$17/mo
Free plan Yes Yes Yes
Works with Claude Code No No Yes

Rating breakdown

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

AttributeDeepSeekDuck.aiPerplexity
Overall rating3.84.04.2Winner
Ease of useHow quickly someone non-technical gets value from it.
3.5
4.5
4.5
FeaturesHow completely it covers its own job, and how well the pieces fit together.
3.0
3.0
3.5
Output qualityHow good the results are before you fix them.
4.0
3.5
4.5
Value for moneyWhat you get for the price, including the free plan.
5.0
4.5
4.0
Speed & reliabilityHow fast it is and how often it falls over.
3.5
4.5
4.5

Feature comparison

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

AttributeDeepSeekDuck.aiPerplexity
Access & platform
Free plan Yes Yes Yes
Mobile app Yes Yes Yes
Desktop app No Yes Yes
Browser extension No Yes Yes
API access Yes No Yes
Teams & business
Team workspace No No Yes
Enterprise plan or SSO No No Yes
Connects to other apps No No Yes
Open source or self-hosted Yes No No
AI abilities
Works with your files Yes Yes Yes
Understands images Yes Yes Yes
Makes images No Yes Yes
Makes video No No Yes
Writes code Yes Yes Yes
Runs agents or automations No No Yes
Learns your brand or style No No No
Works in many languages Yes Yes Yes
Capabilities score8/ 179/ 1715/ 17

Pricing

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

AttributeDeepSeekDuck.aiPerplexity
Plans

Chat appOur pick

Free

Anyone who wants a capable reasoning assistant at no cost.

FreeOur pick

Free

Quick private questions with no sign-up.

Free

Free

Everyday questions and quick fact-checks.

API (deepseek-flash)

Pay per use, from $0.15 per million input tokens

Developers building cheap features into their own apps.

Plus

$9.99/mo or $99.99/yr

Regular users who also want a VPN.

ProOur pick

$17/mo billed yearly

Anyone who researches as part of their job.

API (deepseek-v4-pro)

Pay per use, from $0.66 per million input tokens

Developers who want the stronger model.

Pro

$19.99/mo or $199.99/yr

People who want the top models privately.

Max

$167/mo billed yearly

Power users running the Computer agent all day.

Enterprise Pro

$34/seat/mo billed yearly

Teams that need admin controls and data protection.

Enterprise Max

$271/seat/mo billed yearly

Research teams working with large datasets and files.

Which plan to pickThe app is free, so the only decision is whether the privacy trade-off is acceptable for what you're asking. If you need the model inside your own software, have a developer use the API or run the open model through a provider that keeps your data in Australia.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.Start free and see how often you hit the Pro search limit. If you research most days, Pro pays for itself in saved tabs. Its 4,000 bonus Computer credits are a one-off and run out after about 30 days, so don't count them as a monthly allowance. Max only makes sense if you're using the Computer agent heavily enough to burn through the credits.

Key features

AttributeDeepSeekDuck.aiPerplexity
Standout features
  • Step-by-step reasoning
  • Free app
  • Open models
  • Cheap API
  • Code help
  • No account needed
  • Anonymised prompts
  • Choice of models
  • Voice chat and images
  • Local chat history
  • Built into the browser
  • Cited answers
  • Deep research
  • Comet browser
  • Computer
  • Spaces
  • Choice of models

Pros and cons

AttributeDeepSeekDuck.aiPerplexity
Pros
  • Free app with no paid tier, and strong at reasoning and code
  • API costs a fraction of the big US labs
  • Models are open, so you can run them where your data rules allow
  • Shows its reasoning so mistakes are easier to catch
  • 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
  • Sources on every answer make it the easiest assistant to fact-check
  • Short, direct answers instead of padded essays
  • Free plan is useful on its own and Comet is free
  • Lets you pick from the best models from several companies
  • Fast, and the mobile app is good
Cons
  • Data goes to China and it's banned on Australian government devices
  • No image or video generation and almost no integrations
  • Service slows or drops out when demand spikes
  • Avoids or slants topics sensitive to the Chinese government
  • Writing quality is behind Claude and ChatGPT
  • 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
  • Weak for long writing, planning or creative work
  • Computer credits are confusing: Pro's bonus credits expire after about 30 days, and Comet's browser actions and Automations spend them
  • Sources are sometimes low quality, so you still need to read them
  • Max is expensive for what most businesses need

Who each one is for

AttributeDeepSeekDuck.aiPerplexity
Best for
  • Maths, logic and step-by-step problems
  • Coding help
  • A capable free assistant
  • Cheap API access for your own apps
  • Quick private questions
  • Using AI without signing up
  • A shared or work computer
  • Voice chat and simple image making
  • Fact-checking and quick research
  • Competitor and market research
  • Comparing products before you buy
  • Getting up to speed on a new topic
You'll find it used by
  • Developers
  • Students
  • Analysts
  • Budget-conscious founders
  • Privacy-minded professionals
  • DuckDuckGo users
  • Casual AI users
  • Students
  • Researchers
  • Marketers
  • Consultants
  • Founders

Questions people ask

Which is better, DeepSeek, Duck.ai or Perplexity?

Perplexity scores highest overall in our ratings (DeepSeek 3.8/5, Duck.ai 4.0/5 and Perplexity 4.2/5). DeepSeek is best for Maths, logic and step-by-step problems and coding help. Duck.ai is best for quick private questions and Using AI without signing up. Perplexity is best for fact-checking and quick research and competitor and market research.

Which is cheaper, DeepSeek, Duck.ai or Perplexity?

DeepSeek: There's a free plan, and paid plans start at Pay per use. Duck.ai: There's a free plan, and paid plans start at $9.99/mo or $99.99/yr. Perplexity: There's a free plan, and paid plans start at $17/mo.

How we compare

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

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