How often are AI engines actually updating their index?
I keep getting asked this in customer conversations and don't have a great answer.
From what I've measured directly (not from vendor PR):
- Perplexity: roughly weekly for high-signal sites, can be days for fresh well-structured content. Reddit/HN posts get pulled almost real-time.
- ChatGPT (browsing mode): 2–6 weeks for new pages to show up in citations. Brand-name probes lag longer.
- Google AI Mode: tied to Google's regular crawl cadence, so days-to-weeks depending on site authority.
This matters because the 'wait two weeks then re-scan' rule of thumb is too short for ChatGPT updates and too long for Perplexity.
Questions:
- Does anyone have systematic data on this?
- For high-cadence niches (eg. AI tooling, where the landscape moves weekly), are you tracking changes more aggressively?
5 replies
- Ada K.
For high-cadence niches I scan Perplexity weekly and ChatGPT bi-weekly. Daily is definitely noise — got burned early by over-reacting to single-run variance on a query where 5 brands are basically tied. Now I use 5 runs per prompt and take the majority result before drawing any conclusions.
- Inês Pereira
The training vs retrieval distinction matters a lot here. For 'wait time after publishing content', ChatGPT retrieval (web search on) is weeks. ChatGPT training-corpus is months. Perplexity retrieval is days. Google AI Mode retrieval is tied to Googlebot which for our site is days. Treating them all the same is where most confusion comes from.
- Petr VlčekFounder
Petr here — your week / 2-6 weeks / Google-crawl-tied framing matches what we see closely. One refinement: ChatGPT picks up press hits and Wikipedia edits faster than it picks up blog/product pages. We've seen TechCrunch coverage cited within 6-9 days on average, vs a new product page taking 3-5 weeks. So if you're trying to move ChatGPT fast, the channel matters more than the calendar.
- Jess Wright
ngl this changed how i think about content republish cadence. We've been refreshing posts on a fixed quarterly rhythm, but if Perplexity reads weekly and ChatGPT reads monthly, refreshing the 5 Perplexity-cited posts weekly probably moves more pipeline than blanket-refreshing 50 posts quarterly. Going to test that next month.
From my own testing on a devtool site: Perplexity re-crawled a newly published page within 72 hours when that page had an inbound link from a DR 45+ site. No inbound links = 5-7 days. ChatGPT search-on mode picked up the same page in 14 days. Without web search, still not reflecting it 6 weeks later.