Cycle Route Planning - Desktop systems
There are lots of websites for planning routes online and downloading the route files to a navigation device (smartphone or GPS):
Websites I use the most - each has a page giving further details
RideWithGPS Excellent free route planning with export and import - can use Google streetview when planning. Full details on how to use it are on my RideWithGPS page
Walkhighlands Plot routes on OS maps and export GPX or KML. Full details on how to use it are on my Walkhighlands page
Google My Maps Plot, import routes, add place markers. Export KML/KMZ. I use this a lot for embedding route maps on websites. No Streetview.
Other websites
Gpsies Another excellent free route planning system - can combine routes - convert route files. Part of AllTrails.
BikeHike Dual screen with OS and Google maps (error loading Google map).
CycleStreets Suggests fastest, quietest and balanced routes between 2 points. Can't adjust waypoints.
Google Maps Cycling directions - can be adjusted. No export. Use Streetview to check access.
Bing Maps Get directions and adjust route on OS maps. Save to personal Collections. Embed on website.
The-hug.net Click out a route on OS or WayMaps maps and download GPX file, or upload GPX files.
Veloroutes Plot routes with elevation profiles.
Gmap Pedometer Click out a route, following roads, on various map layers. Save and export.
Osola's GPS Uploader Upload a GPX file to OS Maps or French IGN Maps.
OS Explore Limited use of online OS maps with free account.