Updated
Updated What changed on
- Removed the claim that Perplexity cites content updated within hours 38% more often. It was sourced to convertmate.io, which no longer resolves on any public DNS server, so the figure cannot be checked.
- Replaced it with what Ahrefs measured across 17 million citations: Perplexity orders its in-text references newest first, while the pages it cites average 1,166 days old.
ChatGPT vs Perplexity: which to optimise for first.
The 30-second verdict
For UK B2B audiences, ChatGPT is priority one (78% UK chatbot share vs Perplexity's 5.7%). For research-heavy, technical or academic audiences, Perplexity's footnote-citation transparency and stronger recency bias make it a higher-leverage surface. About 70% of the optimisation work overlaps. The 30% that differs: Bing index health for ChatGPT, recency hygiene + named-author signal for Perplexity. Most UK B2B brands should optimise both with weighted attention.
Side-by-side comparison
 ChatGPT |  Perplexity | |
|---|---|---|
| UK chatbot share (StatCounter Dec 2025) | 78.31% | 5.67% |
| Audience skew | Mainstream consumer + B2B | Research-heavy / technical / academic |
| Citation prominence | Partial - shown in browsing answers | Always - numbered footnotes |
| Reddit citation rate (Ahrefs) | 1.93% (retrieved 67.8% for context) | 24-46.7% (much higher) |
| Live web crawler | OAI-SearchBot + Bing index + Google paid tier | PerplexityBot + own real-time crawl |
| Recency weighting | Orders references newest first | Orders references newest first, but cited pages still average 1,166 days old (Ahrefs measured 17 million citations) |
| Source authority weighting | Mixed - lots of Reddit-for-context | Heavy - news + established publishers dominate |
| Pricing for users | Free + ChatGPT Plus ($20/mo) + Go (ad-supported, testing) | Free + Pro ($20/mo) |
| UK B2B priority | 1st | 3rd-4th depending on audience |
| Optimisation lever | Bing index health + extractable content | Recency + named author + credible sources |
When to pick which
Optimise for ChatGPT first if
Your audience is mainstream UK B2B - law firms, accountants, manufacturers, estate agents, mid-market SaaS. ChatGPT's UK share is large enough that visibility here drives more measurable conversation than any other AI engine. Use the how to rank in ChatGPT guide for the engine-specific work once the shared GEO basics are in place.
Optimise for Perplexity first if
Your audience is research-heavy - academic, technical, financial analyst, journalism, deep-dive consultancy buyers. Perplexity's citation density per response is the highest of any major engine and the audience self-selects for "I want sources I can verify".
Optimise for both (most brands)
About 70% of the work overlaps - schema, named author, content depth, ranking foundations. Build that foundation once and you cover both engines. Then add the 30% engine-specific layer: Bing visibility + GPTBot access for ChatGPT, and an accurate dateModified for Perplexity so a genuinely revised page is read as revised.
The honest read on differences
The biggest practical difference is what each engine treats as a credible source. ChatGPT pulls context from Reddit constantly but cites the major publisher web instead. Perplexity is more publisher-and-Reddit balanced and shows the citation pattern openly. If you cannot diagnose why a competitor is being cited in Perplexity, you usually can - the footnotes are right there. ChatGPT is harder to audit because the citations are less consistent.
The second-biggest difference is recency. Perplexity's freshness weighting is unusually aggressive. Updating a page that already ranks can lift Perplexity citation share within days. ChatGPT does not respond to recency anywhere near as strongly.
What I see when I run the same prompt through both
To make the difference concrete, three queries I ran through ChatGPT (browsing on) and Perplexity Pro on the same day. The patterns hold across most categories I have tested.
- "Best UK GEO consultant" - ChatGPT named 4 sources, mostly agency landing pages without inline citations. Perplexity listed 6 sources with footnotes, including 2 independent consultants and a Search Engine Land article. Perplexity's response was harder to skim but easier to verify.
- "What does generative engine optimisation cost in the UK" - ChatGPT gave a paragraph answer with £-band estimates and no source attribution. Perplexity gave a structured answer citing 4 distinct pricing sources including a 3chillies blog post and a UK agency listicle. For buyer-research queries Perplexity wins on trust.
- "How to fix robots.txt for ChatGPT" - ChatGPT gave the most useful technical answer (it knows its own bot policies best). Perplexity gave a more cautious answer citing OpenAI's docs and one Stack Overflow thread. For ChatGPT-specific technical queries, ChatGPT is better.
Takeaway: prompt type drives engine preference. Buyer-research queries favour Perplexity. Technical / implementation queries favour ChatGPT. Most B2B brands need to be cited in both because the buyer journey passes through both modes.
Agentic actions: where both engines are heading
Both engines are moving toward agentic flows (booking, buying, scheduling, ordering on the user's behalf) in 2026. ChatGPT shipped Operator + Tasks. Perplexity launched Comet (the agent browser). Google AI Mode shipped agentic in the UK in mid-2025.
The practical implication for SEO/GEO: optimise the booking and transaction flows now, not just the content. Schema for ProfessionalService availability, OpeningHoursSpecification, Reservation, Order - these become directly actionable in agentic flows. Pages that an AI agent can transact against will be cited and recommended more. Pages that require human form-filling will get cut out of the agentic path.
More on the comparison.
Which is better for SEO, ChatGPT or Perplexity?
For UK B2B audiences, ChatGPT is higher priority (78% UK chatbot share vs Perplexity 5.7% per StatCounter Dec 2025). For research-heavy / academic / technical audiences, Perplexity's footnote-style citations and recency bias make it the stronger surface. Most brands need to optimise for both with different content tactics per engine.
Does ChatGPT or Perplexity cite Reddit more?
Perplexity cites Reddit far more. Ahrefs found ChatGPT cites Reddit in only 1.93% of answers (despite retrieving it 67.8% of the time for context). Perplexity citations are 24-46.7% from Reddit depending on the study. Reddit presence matters much more for Perplexity than for ChatGPT.
Which has better citation transparency?
Perplexity. Every answer shows numbered footnote citations with source URLs. ChatGPT browsing shows citations but less consistently and less prominently. If you are diagnosing why your brand appears or doesn't, Perplexity is easier to audit.
Which has the bigger UK audience?
ChatGPT by a wide margin. StatCounter UK December 2025 chatbot share: ChatGPT 78.31%, Copilot 11.7%, Perplexity 5.67%. The gap is real and increasing. Perplexity's lower share is offset by higher citation density per response and a more research-intent audience.
Do they share content optimisation work?
About 70% of the work overlaps - schema, named author, content depth, ranking foundations. The 30% that differs: Bing index health matters most for ChatGPT (live browsing uses Bing); recency matters more for where Perplexity places a citation than for whether you get one. Ahrefs found Perplexity and ChatGPT order in-text references newest first, while the pages Perplexity cites average 1,166 days old.
Jason Burns
Independent UK SEO, GEO and AI consultant. 17 years in search. Portfolio includes 3M, BlackRock, Unilever and E.ON. Owner of SEO Moves Ltd since 2014.
More about Jason →Want to see where your brand sits on both engines?
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