Perplexity

Perplexity is an AI search engine, and it addresses the biggest problem with general chat models: you cannot tell whether an answer is real or invented. Here each claim carries a source link you can open and check. For information that leaves your desk — a report, a piece of research, technical reference — that difference is decisive.

Against traditional search, its value is reading the top results for you before answering, rather than handing you ten links. On a specific factual question the time saved is substantial. You can also keep asking follow-ups; it retains context, so a question can be taken deeper step by step.

It is not the tool for creative or long-form output; that is not what it is for. And a caution: having a source is not the same as having a good one. It cites low-quality pages often enough that the links still deserve a glance.

Key features

• Cited answers: it searches the web and writes an answer with numbered sources on each claim, linking straight to the originals.
• Follow-up questions: keep asking in the same thread and it searches again with the earlier context.
• Deep research: for complex questions it runs multiple rounds of searching and writes a fuller report, taking longer to do so.
• Source focus: narrow the search to specific kinds of sources, such as academic papers or discussion forums.
• Files and spaces: upload files to ask about alongside the web, and group related searches into a shared space.

How to use

1. Open the website or download the app; you can search without signing in, and signing in saves your history.
2. Ask a full question the way you would ask a person rather than typing keywords; answers are more accurate.
3. Watch the source numbers as you read, and open the originals for any conclusion that matters.
4. For complex topics, switch to deep research or narrow things down with follow-ups.

Best for

• Fact-checking: confirming where a figure or claim comes from.
• Quick research: a sourced overview when entering an unfamiliar field.
• Technical lookups: API usage and error causes, faster than opening several pages.
• Gathering material before writing a report, since the links make later citation easy.

Strengths and limitations

Strengths

• Every claim can be traced, so checking is cheap.
• Direct answers without opening search results one by one.
• The free tier is enough for everyday use; a subscription lets you choose stronger models.

Limitations

• A source is not necessarily a good one; it often cites low-quality pages.
• Not suited to creative writing or long-form output.
• Coverage of Chinese-language material trails domestic Chinese alternatives.
• Not reachable from mainland China directly.