YandexAdditionalBot
YandexAdditionalBot is a training crawler operated by Yandex. Its job is to read public web pages and feed that content into a machine-learning pipeline that trains future versions of the model.
Unlike a search-engine crawler, a training crawler does not send users back to your site. The content is consumed once, baked into the model, and shows up later in the model's responses. There is usually no citation and no referral traffic.
If Yandex ships a new model version, you will likely see YandexAdditionalBot traffic spike for a few weeks while it gathers fresh data, then quiet down again.
See YandexAdditionalBot 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
Periodic, broad
Honors robots.txt
Yes
Honors Crawl-delay
No
Yandex runs 34 bots in total. Each one is a separate user-agent so you can allow or block them independently.
Link Unfurler
16Search Engine
13Training Crawler
2- YandexAdditional
- YandexAdditionalBotYou are here
Shopping Bot
2Brand Intelligence
1Should I let YandexAdditionalBot through?
There's a real trade-off here. Training crawlers consume content without sending users back. Decide whether the trade for being in the model is worth your bandwidth. If Yandex actually drives traffic or citations back to you, letting it through usually pays for itself. If it just consumes bandwidth, block it.
Does blocking YandexAdditionalBot affect my Google rankings?
No. YandexAdditionalBot collects training data, not search-index pages. Your classical search rankings stay intact. The actual trade is whether you want your content folded into the next model release.
How do I confirm a request is really from YandexAdditionalBot?
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 YandexAdditionalBot", not "the traffic is genuinely YandexAdditionalBot". If you need stronger guarantees, look for a reverse-DNS check or wait for Yandex to publish IP ranges.
What happens to my content if I let YandexAdditionalBot fetch it?
It gets pulled into Yandex's training pipeline and stored. Whether and how it influences a future model release is rarely disclosed. The only real lever you have on the outcome is what you allow at fetch time.
How is YandexAdditionalBot different from Yandex's other bots?
Yandex 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 Yandex family above to see which ones actually matter for your site.
What's the cleanest way to control YandexAdditionalBot?
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.