
Fluidmaster 5403 Flapper
Score: 92/100
Korky 100BP
Score: 90/100Rankings

The Fluidmaster 5403 is a universal adjustable 3-inch toilet flapper designed for high-efficiency toilets, featuring a durable silicone seal and customizable flush volume settings. It offers a solid frame to prevent twisting and includes an adjustable dial to optimize water usage between 1.28 and 1.6 gallons per flush. It is ideal for quick DIY fixes for ghost flushing, water conservation in homes with hard water or chlorine, and universal replacement in brands like Kohler, Toto, or American Standard.

The Korky 100BP Ultra High Performance Flapper is a universal 2-inch toilet flapper designed to maximize flush performance while conserving water across various gallon-per-flush ratings. Constructed from exclusive chlorine-resistant red rubber, it offers superior durability in harsh water conditions and features adjustable settings for precise water optimization. It is best suited for homeowners with standard 2-inch toilets in areas with chlorinated, hard, or well water.
| Attribute | ![]() | ![]() |
|---|---|---|
3 inchesbest | 2 inches | |
1 countbest | 1 countbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Material & Durability(2) | ||
Material | Silicone | Rubber |
Seal Type | Silicone | Sealing Ball |
Design & Features(1) | ||
Chain Material | Kink-free | Stainless Steel |
Packaging & Support(1) | ||
Warranty Period | 10 Years | 5 Years |
Compatibility & Fit(5) | ||
Flush Valve Compatibility | Universal | 2-inch |
Flapper Diameter (inches) | 3 inches | 2 inches |
Toilet Type Compatibility | High-efficiency | Standard |
GPF Compatibility | 1.28-1.6 | 1.28-5 |
Flush Valve Size | 3 | 2 |


Products in the top-left offer the best value (high score, low price).

Professional reviewers, including Home Improvement expert Bob Vila, highly recommend the Fluidmaster 5403 as the best overall 3-inch flapper for fixing running toilets. Experts praise its universal fit, adjustability, and durable silicone construction, noting that it provides quality you can trust for eliminating leaks in newer high-efficiency toilets.
Everyday consumers generally praise the Fluidmaster 5403 for its ease of installation, water savings, and longevity. Users frequently report that it stops running toilets quickly and fits a wide variety of brands. While some users mention a learning curve for adjustments, the overall sentiment is positive, highlighting its reliability and durability compared to standard flappers.

Professional reviewers and plumbing experts, including those from Clorox, highly endorse the Korky 100BP as the longest-lasting flapper available. Editors at supply sites praise its high performance and precise water control, noting that it significantly outperforms generic brands in chlorine resistance tests. The product is highlighted for its universal design, making it ideal for contractors who need a single solution for various toilet brands, with no performance drop across different flush volumes.
Everyday consumers rave about the product's longevity, with many reporting it lasted up to seven years in harsh water conditions. Users frequently praise the ease of installation, noting it takes only five minutes without tools. Common themes include strong flush performance despite water savings and perfect fits for brands like Kohler. Recurring complaints focus on the chain being too long and occasional initial seal issues that require adjustment.
“lasted 7 years in hard well water”

“5 minutes, no tools”

“saves hundreds of gallons yearly”


