Top-tier bottles: yes, on the top rack
Modern Yeti Ramblers, Stanley Quenchers, Hydro Flask newer models, and Nalgene bottles are all dishwasher safe on the top rack. The insulation isn't affected by the dishwasher's heat — the vacuum seal is completely sealed off from the water and detergent, so the wash cycle can't degrade it.
Always remove the lid and any rubber gaskets before loading. Wash those separately on the top rack as well. Let everything air-dry completely before reassembling to make sure no moisture gets trapped inside, which could encourage mold or odor.
Hydro Flask: check the age
Hydro Flask changed its design to be dishwasher safe, but older models are hand-wash only. The way to tell: older Hydro Flasks have a trademark (™) symbol next to the logo on the bottom. If you see it, hand wash. Newer bottles without the ™ are the dishwasher-safe generation.
This distinction matters because older Hydro Flasks have a different seal design that can be compromised by heat and water pressure. When in doubt, hand wash any vintage Hydro Flask to be safe.
The lid and gasket rule
Never put a lid in the dishwasher without removing the gasket first. Rubber gaskets and silicone rings don't benefit from the harsh detergent and hot water — they'll degrade over time and may eventually fail, causing leaks. Remove them, wash them by hand with warm soapy water, and let them air-dry.
Plastic lids themselves can handle the top rack, but letting them air-dry instead of heat-dry extends their life. If your dishwasher has a heated dry cycle, skip it for lids and bottles; just use the normal or air-dry setting.
Hand washing is still the safest option
Even though most bottles are labeled dishwasher safe, many people hand wash them anyway. A quick rinse with hot water and bottle brush takes two minutes and keeps the finish looking newer longer. The powder-coat paint on Stanley and Yeti bottles, while durable, can dull or fade after many harsh dishwasher cycles.
For bottles you use daily and care about long-term, hand washing is the wise choice. For quick cleanups or when you're in a hurry, the dishwasher is fine. The bottle will outlast several dishwashers, but hand washing keeps it looking fresh for longer.