The WSXGA+ Wallpaper size (1680×1050px)
1680x1050 pixels is a 16:10 resolution called WSXGA+, the native size of many 22-inch monitors and higher-end laptops from the 16:10 era. Like all 16:10 panels, it is a touch taller than 16:9, so a widescreen wallpaper made for 1080p or 1440p will not fit cleanly, leaving bars or losing the sides to cropping.
Resizing to a true 1680x1050 solves that. The 16:10 canvas fills a WSXGA+ display edge to edge with your full composition and no distortion, which is exactly what you want when the wallpaper is meant to sit behind your work all day. On these productivity-oriented panels the extra vertical space is part of the appeal, so a properly proportioned image respects that shape.
Since WSXGA+ is a mid-resolution standard, there is no advantage to a huge source file beyond ensuring it is at least 1680x1050; the panel renders 1050 vertical lines and no more. Resizing to this exact size hands the display what it can show and keeps the result crisp. Keep the key subject centered and clear of the taskbar and icon columns. The resize runs entirely in your browser, so your image is never uploaded, it costs nothing, and your original quality is preserved while the file is locked to the 16:10 shape a WSXGA+ monitor needs. Panel specs vary, so verify yours.