Who this is for
eBay sellers who want to understand how search actually works—not vague advice like "use good keywords." If you've ever wondered why some listings rank above yours despite similar titles, Cassini is the answer.
Generate optimized eBay titles
Create keyword-packed 80-character titles that rank in Cassini search.
The goal
Learn what Cassini measures, what it rewards, and what it penalizes. By the end of this guide, you'll know exactly which factors to optimize for better search visibility.
What is Cassini?
Cassini is eBay's search engine. Named after the NASA spacecraft (eBay's engineers apparently liked space), it replaced the older Voyager search system in 2013 and has been continuously updated since. In 2026, Cassini remains eBay's core search algorithm, with ongoing refinements to prioritize buyer experience and seller reliability.
When a buyer searches for "vintage leather jacket size medium," Cassini decides which of the millions of matching listings to show first. Your job is to give Cassini the signals it needs to rank your listing above competitors.
How Cassini ranks listings
Cassini uses three main categories of signals, weighted to prioritize buyer experience:
- Relevance — Does your listing match what the buyer searched? (~40-50% weight)
- Seller performance — Are you a reliable seller? (~30-40% weight)
- Listing quality — Is your listing complete and trustworthy? (~20-30% weight)
While eBay doesn't publish exact weights, seller testing and eBay's official statements indicate relevance matters most, followed by seller metrics. A perfectly relevant listing from a poor-performing seller will still underperform a slightly less relevant listing from a Top Rated Seller.
Each factor contributes to your overall search placement. Let's break them down.
Generate optimized eBay titles
Create keyword-packed 80-character titles that rank in Cassini search.
1. Relevance factors
Title keyword matching
Cassini reads your title to determine if your listing matches a search query. It looks for:
- Exact phrase matches — "vintage leather jacket" matches the search exactly
- All words present — The search terms appear in your title, even if not adjacent
- Word order — Earlier placement of keywords may carry more weight
What works: ``` Vintage Leather Jacket Mens Size Medium Brown Bomber Motorcycle ```
What doesn't: ``` L@@K!! AMAZING Jacket WOW Great Gift Must See RARE!!! ```
The first title contains searchable keywords. The second wastes characters on filler that nobody searches for.
For detailed title optimization, see our eBay title guide. For overall selling strategies, check our eBay selling guide.
Item specifics
Item specifics (Brand, Size, Color, Material, etc.) are fully indexed by Cassini. When a buyer filters search results by "Size: Medium" or "Brand: Levi's," only listings with those specifics appear.
Incomplete item specifics = invisible in filtered searches.
Fill in every available field. If eBay suggests an item specific for your category, complete it. The more specifics you provide, the more filtered searches can find you.
Category placement
Listing in the wrong category hurts visibility. If you list a leather jacket under "Coats & Jackets" but buyers search in "Motorcycle Jackets," you won't appear in their results.
eBay sometimes suggests categories—take those suggestions seriously. They're based on what buyers actually search.
2. Seller performance factors
Seller level and metrics
eBay tracks your performance through:
- Defect rate — Transaction problems (cancellations, cases closed without resolution)
- Late shipment rate — Orders shipped after the stated handling time
- Tracking validation — Percentage of orders with uploaded, valid tracking
Top Rated Sellers get a search boost. If your metrics slip below standard, your listings may be suppressed.
On-time shipping
Cassini favors listings with fast, reliable shipping. Factors that help:
- Same-day or 1-day handling time
- Free shipping (eBay has confirmed this is a ranking factor)
- Tracking uploaded within handling time
Listings with long handling times (5+ days) may rank lower than identical listings with 1-day handling.
Return policy
Generous return policies correlate with better placement. A 30-day free return policy signals buyer confidence. No returns accepted may hurt your visibility.
3. Listing quality factors
Photos
Cassini doesn't "see" your photos, but it measures buyer behavior. Listings with clear, professional photos get more clicks. More clicks signal to Cassini that the listing is relevant.
Minimum requirements:
- 1600px on longest side
- White or neutral background
- No watermarks or text overlays
For photo optimization, see our eBay photo requirements guide.
Price competitiveness
Cassini considers price relative to similar listings. A $50 leather jacket competes differently than a $500 one. Being significantly overpriced compared to similar items may reduce visibility.
Best Offer enabled also helps. eBay has stated that Best Offer listings may receive preference in Best Match results.
Buyer engagement signals
Cassini tracks how buyers interact with your listings:
- Click-through rate (CTR) — How often your listing gets clicked when shown in search
- Conversion rate — Percentage of viewers who purchase
- Time on listing — How long buyers spend viewing your listing
- Add to watchlist rate — Indicates buyer interest
Listings with strong engagement signals rank higher over time. This creates a feedback loop: better placement → more visibility → more clicks → even better placement.
Listing format
Auction vs. Fixed Price: For Best Match searches, fixed-price listings often rank higher because they represent stable inventory. Auctions may appear higher when ending soon (the "ending soonest" boost).
Good 'Til Cancelled: GTC listings that sell well accumulate sales history, which may improve their ranking over time.
What Cassini doesn't care about
Based on eBay's statements and seller testing, these factors have minimal or no impact:
- Description content — Cassini doesn't index descriptions for search. Descriptions affect conversion, not ranking. For description best practices, see our eBay description compliance guide.
- Number of watchers — Watchers don't directly boost search rank (though they may indicate demand).
- How long you've been selling — Account age isn't a ranking factor.
- Social media links — External traffic doesn't boost eBay search rank.
What changed in 2025-2026
eBay continues to refine Cassini with incremental updates. Recent changes include:
Increased weight on seller metrics
Top Rated Sellers with Above Standard performance now see stronger search preference compared to Standard sellers. The gap between performance tiers has widened—maintaining Top Rated status is more valuable than ever.
Enhanced item specifics indexing
eBay expanded item specifics across multiple categories in 2025. Categories that previously had 5-10 specifics now have 20+. Completing all available specifics is now table stakes, not an advantage.
Mobile-first ranking signals
With 75%+ of eBay traffic on mobile, Cassini now weights mobile-specific signals more heavily:
- Mobile photo quality (readable on small screens)
- Mobile-optimized title length (first 40 characters matter most on mobile)
- Quick-loading listings (oversized images hurt mobile rank)
Return policy emphasis
eBay's "eBay Money Back Guarantee" made return policies more prominent in 2025. Listings with 30-day or longer free returns now show a "Free returns" badge in search results, which improves CTR and indirectly boosts rank.
Fast shipping requirements
Same-day and next-day handling times now carry more weight. Sellers offering 1-day handling see measurably better placement than 3-day handling, especially in competitive categories.
Common Cassini myths
"Ending soon auctions always rank first"
Only partially true. Ending soon is one factor, but fixed-price listings with strong relevance and seller metrics can outrank ending auctions.
"More listings = better visibility"
Having 1,000 listings doesn't boost individual listing rank. Each listing competes on its own merits. However, more listings mean more chances to appear in different searches.
"Relisting resets your ranking"
Relisting doesn't give you a "freshness boost." Sales history and watch count typically carry over. Ending and relisting to manipulate rank doesn't work.
"eBay suppresses sellers to force ads"
No evidence supports this. Promoted Listings pay for guaranteed placement above organic results, but organic ranking follows the same algorithm for all sellers.
How to optimize for Cassini
Quick wins (do these today)
- Complete all item specifics — Fill every field eBay offers for your category
- Enable free shipping — Even if you build it into the price
- Offer free returns — 30 days minimum
- Set 1-day handling time — If you can reliably ship same or next day
- Enable Best Offer — On fixed-price listings
Title optimization
- Use all 80 characters with searchable keywords
- Front-load the most important terms (brand, product type)
- Skip filler words (L@@K, WOW, AMAZING, RARE unless actually rare)
- Include size, color, and condition where relevant
See our complete eBay title guide.
Maintain seller metrics
- Ship on time, every time
- Upload tracking immediately
- Respond to buyer messages within 24 hours
- Resolve issues before they become defects
Price competitively
- Research completed listings for realistic pricing
- Use Best Offer to capture buyers at different price points
- Consider Promoted Listings for competitive categories
Promoted Listings vs. organic rank
Promoted Listings are eBay's advertising system. You pay a percentage of the sale price for guaranteed placement above organic results.
Promoted Listings don't affect organic rank. They're a separate placement. If you stop promoting, your organic position remains unchanged.
When to use Promoted Listings:
- Competitive categories with many similar listings
- New listings without sales history
- Seasonal inventory you need to move quickly
When organic is enough:
- Unique items with few competitors
- Strong seller metrics already
- Categories with lower competition
FAQ
Does eBay still use Cassini in 2026?
Yes. Cassini remains eBay's core search algorithm as of 2026. While eBay continuously updates and refines how Cassini works, the fundamental system has been in place since 2013. The name "Cassini" is used less frequently in official eBay documentation, but the underlying search engine is the same system, continuously evolved.
How does eBay's search algorithm work in 2026?
eBay's Cassini algorithm ranks listings based on three weighted factors: relevance to the search query (40-50%), seller performance metrics (30-40%), and listing quality signals (20-30%). The algorithm evaluates title keyword matches, item specifics, seller defect rate, shipping speed, pricing competitiveness, and buyer engagement signals like click-through rate and conversion rate. Listings that match all three categories rank highest.
How to rank higher on eBay search?
To rank higher in eBay search:
- Use exact keyword matches in your title (front-load important terms)
- Complete all item specifics for your category
- Maintain Top Rated Seller status with low defect rate
- Offer 1-day handling time and free shipping
- Enable 30-day free returns
- Price competitively and enable Best Offer
- Use high-quality photos (1600px+)
- Choose the correct category
See our eBay selling guide for comprehensive optimization strategies.
How long does it take for Cassini to rank a new listing?
New listings are indexed almost immediately (within minutes to hours). However, listings with sales history may outrank brand-new ones for competitive searches.
Does Cassini favor certain categories?
No category-wide favoritism exists. However, some categories are more competitive than others, making it harder to rank for popular searches.
Can I see my Cassini ranking?
Not directly. eBay doesn't provide a "rank" number. You can search for your own products and see where you appear, but rankings fluctuate based on buyer location, search history, and other factors.
How often does Cassini update?
Continuously. Rankings can shift based on real-time factors like competing listings, your seller metrics, and buyer behavior patterns.
Does mobile search use a different algorithm?
The core algorithm is the same, but mobile results display differently (fewer visible at once). Mobile optimization matters because most eBay traffic is mobile—ensure your photos and titles work on small screens.
What's the difference between Best Match and other sort options?
Best Match is Cassini's default ranking. Other sort options (Price + Shipping: lowest first, Ending soonest, etc.) override Cassini and sort by that single factor instead.
Cassini optimization checklist
Before listing, verify:
- Title uses all 80 characters with relevant keywords
- All item specifics completed
- Category matches what buyers would search
- Photos are 1600px+, clear, white background
- Free shipping enabled (or competitive shipping cost)
- Returns accepted (30 days preferred)
- Handling time is 1 day if you can maintain it
- Price is competitive with completed listings
- Best Offer enabled on fixed-price listings
Next steps
- Audit your listings — Check item specifics completion and shipping settings
- Optimize your titles with our eBay title guide
- Improve your photos using our eBay photo requirements
- Monitor seller metrics in Seller Hub to maintain Top Rated status
For automated listing optimization, try our eBay listing generator to create Cassini-friendly titles and descriptions.
Generate optimized eBay titles
Create keyword-packed 80-character titles that rank in Cassini search.
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