Amazon A9 is the original search algorithm that ranks products mainly by keyword relevance and sales velocity. A10 is the sellers' name for its evolved version, which puts more weight on relevance, genuine conversion, organic sales, and seller authority. In short, A9 rewarded volume and A10 rewards quality. Optimizing for A10 means matching real intent and converting shoppers, not gaming velocity.
TL;DR
- A9 is Amazon's original algorithm, focused on keyword match and sales velocity.
- A10 is the informal name for its updated version, weighting relevance, organic conversion, and seller authority more heavily.
- Amazon never officially named either; sellers coined the terms to describe observed shifts.
- The practical change: A9 rewarded raw sales, A10 rewards satisfying real buyer intent.
- Optimizing for A10 means relevant keywords, high conversion, organic sales, strong account health, and honest reviews.
- Managing all those signals across a catalog by hand is exactly what an AI operator does for you.
What is the Amazon A9 algorithm?
The Amazon A9 algorithm is Amazon's original product search engine, named after the A9.com subsidiary that built it. Its core job is to match a shopper's search query to relevant products and then rank them, leaning heavily on two things: keyword relevance and sales velocity. Products that matched the query and sold fast rose to the top.
A9 made Amazon's search feel simple to game. Put the right keywords in your title and backend fields, drive sales through ads and promotions, and you climbed. This worked because A9 treated a sale as a sale, whether it came from organic search, a Sponsored Products ad, or an external promotion. With Amazon capturing roughly 40% of US ecommerce sales, that ranking system decided where billions of dollars in demand flowed, so sellers optimized aggressively for it.
What is the Amazon A10 algorithm?
The Amazon A10 algorithm is the informal name sellers gave to the updated version of Amazon's search system after they noticed its ranking behavior shift. A10 still matches queries to products, but it puts more weight on relevance, genuine buyer satisfaction, organic conversion, and seller authority. It rewards listings that real shoppers want, not just listings that generated velocity.
The key change is how A10 treats the source of sales. Under A9, an ad-driven sale counted almost the same as an organic one. A10 gives more credit to organic sales, the ones that come from shoppers finding and choosing your product on their own. That signals genuine demand. Amazon Ads guidance confirms that conversion rate is a core input to organic ranking, and A10 leans into that: a product that converts browsers into buyers, keeps them satisfied, and earns repeat purchases outranks one that just spent its way to visibility.
A9 vs A10: what actually changed?
The shift from A9 to A10 is a move from volume to quality. Both algorithms match keywords and rank products, but they weight the signals differently. Here is a direct comparison of what each one prioritizes.
| Ranking factor | A9 weight | A10 weight |
|---|---|---|
| Keyword relevance | High | High |
| Sales velocity | Very high | Moderate |
| Organic sales vs paid | Treated similarly | Organic favored |
| Conversion rate | Moderate | Very high |
| Seller authority and history | Low | High |
| Product reviews and rating | Moderate | High |
| External traffic | Low | Moderate |
| Buyer intent match | Moderate | Very high |
The pattern is clear. A9 could be pushed with aggressive advertising and keyword stuffing. A10 rewards listings that satisfy the shopper: relevant to the query, high-converting, well-reviewed, and backed by a healthy seller account. According to the Jungle Scout State of the Amazon Seller Report, the most successful sellers now focus on conversion and product quality over raw traffic, which lines up exactly with how A10 behaves.
What are the key A10 ranking factors?
A10 ranks products on a blend of relevance, conversion, and trust signals. No single factor wins on its own; they compound. These are the levers that move rank most:
- Keyword relevance: your product must be indexed for the query. If the term is not in your title, bullets, or backend keywords, you cannot rank for it. Our backend keywords guide covers where hidden terms go.
- Organic sales: sales that come from search, not ads, carry the most ranking weight because they prove genuine demand.
- Conversion rate: the percentage of visitors who buy. High conversion tells A10 your listing satisfies intent.
- Seller authority: account age, order defect rate, and account health. Established, reliable sellers get a lift.
- Reviews and rating: volume and star rating both matter. According to Jungle Scout, listings with more reviews convert meaningfully better.
- Click-through rate: how often shoppers click your listing when it appears. Strong images and titles drive this.
The takeaway is that A10 rewards a genuinely good product with a genuinely good listing that genuinely satisfies buyers. There is no keyword trick that substitutes for that.
How do you optimize for the A10 algorithm?
Optimize for A10 by making your listing relevant, high-converting, and backed by real demand. The work splits into two halves: getting indexed for the right queries, then converting the traffic you earn. Follow these steps:
- Nail your keyword coverage. Put your primary keyword in the title (now capped at 75 characters), work secondary terms into bullets, and load synonyms and long-tail phrases into backend search terms.
- Optimize for conversion. Use a clean main image, benefit-led bullets, and A+ Content if you are brand-registered. Every point of conversion rate compounds in A10.
- Prioritize organic sales. Use ads to kickstart velocity, then let organic take over as rank builds. Do not stay dependent on paid traffic.
- Protect account health. Keep your order defect rate low, ship on time, and resolve issues fast. A10 favors trusted sellers.
- Earn reviews compliantly. Use Amazon Vine and the Request a Review button. Reviews lift both rank and conversion.
- Watch price competitiveness. Winning the Buy Box and staying price-competitive supports conversion, which feeds rank.
Our Amazon SEO guide goes deeper on each of these, and our listing optimization guide covers the on-page work in detail. The through-line is simple: A10 stopped rewarding shortcuts and started rewarding genuinely good selling.
Is A9 still relevant, or is it all A10 now?
A9 is not a separate system you can ignore; A10 is the same algorithm, evolved. Amazon does not flip between two engines. It continuously updates one ranking system, and "A9" and "A10" are just sellers' labels for how that system behaved at different points. So the honest answer is that the fundamentals of A9 still apply, they are just no longer enough on their own.
Keyword relevance and sales velocity, the pillars of A9, still matter. You still have to be indexed and you still need sales momentum. What changed is that these are now table stakes, and the extra signals A10 introduced, conversion quality, organic demand, and seller trust, decide who wins among the many products that clear the basics. As Marketplace Pulse has documented, the marketplace keeps getting more crowded, so the tie-breakers matter more every year. Sellers who only optimize the A9 basics plateau. Sellers who also optimize the A10 signals keep climbing.
Frequently asked questions
What is the Amazon A9 algorithm?
The Amazon A9 algorithm is Amazon's original product search system. It ranks listings mainly by keyword relevance and sales velocity, favoring products that match a query and convert quickly. A9 built the foundation for how Amazon matches shoppers to products in search results.
What is the Amazon A10 algorithm?
A10 is the informal name sellers use for Amazon's updated search algorithm. It places more weight on relevance, genuine conversion, seller authority, and organic sales over paid traffic. A10 rewards listings that satisfy real buyer intent rather than those simply optimized for keywords and velocity.
What is the difference between A9 and A10?
A9 leaned heavily on keyword match and raw sales velocity, including sales from ads. A10 shifts weight toward relevance, buyer satisfaction, organic conversion, and seller authority. In short, A9 rewarded volume; A10 rewards quality and genuine shopper intent.
How do I rank on the Amazon A10 algorithm?
Match real search intent with relevant keywords, write listings that convert, earn organic sales rather than relying only on ads, keep account health strong, and collect honest reviews. A10 favors products shoppers actually want and return to, not listings gamed for velocity alone.
Does Amazon officially call it the A10 algorithm?
No. Amazon has never officially named its algorithm A9 or A10. Sellers coined these terms to describe observed changes in ranking behavior. The names are useful shorthand, but the underlying system is one evolving algorithm Amazon updates continuously.
Do ads still help ranking under A10?
Yes, but indirectly. Ads drive sales velocity and visibility that can boost early rank, especially on a new listing. Under A10, though, organic sales carry more ranking weight than ad-driven ones, so ads are best used to kickstart momentum, not to prop up rank permanently.
A10 rewards sellers who optimize everything at once. Jinnify is the operator that does it - it keeps your keywords indexed, your listings converting, your prices competitive, and your reviews flowing, all on autopilot. Instead of another dashboard to manage, it runs the daily optimization A10 rewards. Start for free.
Author: The Jinnify Team - Amazon growth and automation specialists Published: 2026-07-08 | Updated: 2026-07-08 Sources: Amazon Ads product detail page guide, Jungle Scout State of the Amazon Seller Report, eMarketer, Marketplace Pulse