Can You Watch Netflix on a Nintendo DSi XL? No

No. The Nintendo DSi XL (and all DSi models) **cannot run Netflix**.

Technical Reasons

• No Modern Browser: The DSi Shop browser is a stripped-down Opera build that cannot handle DRM video streaming (HTML5/EME, Widevine).
• Insufficient Hardware: 133 MHz ARM9 + 16 MB RAM cannot decode H.264/HEVC video at acceptable framerates.
• No App Ecosystem: Netflix never released a DSiWare app. The DSi Shop closed in 2017; no new apps can be installed.
• No HDMI/Video Out: Even if it could decode, there's no way to output to a TV.

Devices That *Can* Stream Netflix (Budget-Friendly)

• Roku Express / Fire TV Stick Lite: $25–$30, HDMI, full Netflix support.
• Smartphone/Tablet + Chromecast / AirPlay: Cast from mobile app.
• Game Consoles: Wii (Netflix app worked until 2019), Wii U, Switch, PS3/4/5, Xbox 360/One/Series.
• Old Laptop/PC: Browser playback works on Vista+.

The DSi XL is a great handheld for DS games, but it lacks the horsepower and software stack for any modern streaming service.