What we sample
1,842,000+ unique Japanese keywords observed at fixed cadences against Google.co.jp and Yahoo! JAPAN, including vertical surfaces (images, news, maps, shopping) where Japanese intent lives.
PROPRIETARY INDEX · UPDATED DAILY
Japan's definitive measure of search ranking turbulence.
The JP-SERP Volatility Index is the proprietary pulse of how search results actually move across Google.co.jp and Yahoo! JAPAN — built from 1.8M+ daily SERP observations and read every Monday by 141,800+ subscribers.
47% average open rate · cited by Nikkei Digital Gear · trusted by SEO teams at Mercari, Rakuten, Recruit, Sony, and LINE
METHODOLOGY · ANSWER FIRST
What the JP-SERP Volatility Index actually measures — and why a rank tracker cannot replace it.
Generic rank trackers tell you where a URL stood at 09:00. The JP-SERP Volatility Index tells you how violently the entire Japanese results page is rearranging itself, hour by hour, across the two engines that matter in Japan.
How we aggregate
Per-keyword position deltas are normalized against a 30-day baseline, then weighted by query volume (Similarweb Japan keyword demand feed) to produce a single 0–100 composite reading.
What you can do with it
A spike above 65 historically precedes a confirmed core update within 9–14 days. A sustained reading below 30 is the green light to ship aggressive on-page and link changes without false-positive noise.
LIVE FEED · WHAT YOU WOULD SUBSCRIBE TO
The number, and the scale behind the number.
Every Monday, the brief delivers a freshly published JP-SERP Volatility Index reading alongside the daily tracking scale that produced it — so the headline figure is never separated from the evidence.
- Today
- 62.4 · ELEVATED
- 30-day mean
- 58.3
- 52-week high
- 78.1
- 52-week low
- 21.6
- Total daily SERPs
- 1,842,000+
- Google.co.jp
- ~ 62% of feed
- Yahoo! JAPAN
- ~ 38% of feed
- Update cadence
- Every 4 hours
BY THE NUMBERS
The operation, in four figures.
1.84M+
Daily SERP observations across Google.co.jp and Yahoo! JAPAN
12
Full-time bilingual SEO analysts in Tokyo and Osaka
47%
Average open rate on the weekly brief (vs. 21% industry benchmark)
2023
Asia Search Awards — Best Use of Search in Publishing, Independent
EDITORIAL BACKBONE
A data partnership and a 12-person desk. That is the moat.
The index only earns its reputation because it is fed by infrastructure nobody else in the English-language market has assembled. Two pillars: an exclusive Japan keyword demand feed from Similarweb, and a 12-analyst bilingual research team that reads the output in both languages before publication.
Similarweb Japan keyword demand feed
An exclusive partner data feed agreement with Similarweb gives Ranking Japan first-look access to Japan-market keyword demand signals since 2022 — so the volatility readings are weighted by what Japanese users actually search for, not by an English-language volume proxy.
12 analysts, two cities, one brief
A bilingual research team of 12 SEO analysts based in Tokyo and Osaka, supported by 4 contributing editors. Every published figure is reviewed in Japanese against the source SERP before it leaves the desk — a discipline generic rank trackers cannot match.
THE BRIEF · DELIVERED MONDAY 06:00 JST
Get the Weekly Japan SERP Brief in your inbox.
One email, every Monday. The JP-SERP Volatility Index reading, methodology notes, the Yahoo! JAPAN vs. Google.co.jp market-share series, and what the analyst desk thinks it means for the week ahead.
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