PWABuilder
PWABuilder is a generic scraper operated by Microsoft. Intent varies case-by-case, some scrapers are legitimate research, some power useful aggregators, some are abusive.
Look at the request pattern before deciding what to do. A polite scraper crawls slowly, respects robots.txt, and identifies itself. An abusive one ignores all three.
If you are not sure, the safest move is to rate-limit rather than block outright. That keeps the legitimate use cases working while neutralizing the abusive ones.
See PWABuilder on your own site
Match the User-Agent header on incoming requests against the pattern below.
regex
For higher confidence, also verify the source IP against the operator's published ranges. UA strings can be spoofed; IP ownership is harder to fake.
Renders JavaScript
No
IP verification
Published IP ranges
Crawl frequency
Variable
Honors robots.txt
Yes
Honors Crawl-delay
No
Microsoft runs 24 bots in total. Each one is a separate user-agent so you can allow or block them independently.
Link Unfurler
11Search Engine
4AI Search Index
2Agentic Browser
2DevOps & Monitoring
1Generic Crawler
1- PWABuilderYou are here
SEO Crawler
1Should I let PWABuilder through?
Watch your logs for a week first. Behavior varies wildly. Observe the request pattern before allow/block decisions.
Does blocking PWABuilder affect my Google rankings?
No. PWABuilder is not a search-engine crawler. Your ranking on Google or Bing is unaffected by what you do here.
How do I confirm a request is really from PWABuilder?
Look at the User-Agent header in your access logs and match it against the strings listed above. Worth knowing that the User-Agent is easy to fake, so this check tells you "the traffic claims to be PWABuilder", not "the traffic is genuinely PWABuilder". If you need stronger guarantees, look for a reverse-DNS check or wait for Microsoft to publish IP ranges.
What's the best way to understand what PWABuilder is doing on my site?
Look at which URLs it hits, how often, and what time of day. The request pattern usually tells you whether it's building an index, watching for a specific change, or trying to pull data in bulk. The User-Agent name alone rarely tells the full story.
How is PWABuilder different from Microsoft's other bots?
Microsoft splits work across multiple user-agents so site owners can decide on each one independently. Training crawlers, live-fetch agents, search indexers, and agentic browsers each get their own name. Worth scanning the rest of the Microsoft family above to see which ones actually matter for your site.
What's the cleanest way to control PWABuilder?
Two layers. Robots.txt for the polite crawlers that read it, and rules at your CDN or edge for the ones that don't. Rankly's Agent Experience handles both from a single config, so you can allow, block, rate-limit, or serve a stripped-down version per bot. Agent Analytics handles the observation half so you know which bots are actually worth a rule.
Verify everything above against the operator's own documentation.