New Opensnowmap for mobile devices

The new mobile version of Opensnowmap is now available after a major overhaul at

This shouldn’t change a lot of things if you are already used to the mobile website. There is however a new control to get more information about the OpenStreetMap ski pistes data accessible from a simple a tap on the map.


Simply select the arrow from the search menu, and tap the map near a piste. The round cursor can be dragged toward another piste at will.

Under the hood

The 8 years old OpenLayers 2 has been replaced by the excellent version 6 of the map library.

OpenSnowMap summer upgrade

The lower traffic on website during the summer is the opportunity for some maintenance works and map style upgrade in the following weeks.

Database reload – The base topo map database will be reloaded. It has some glitches (some elements are inexplicably missing), and the upcoming style change needs a couple of new columns. Minutely updates will after that be handled by Osmium. New tiles render will be down during a few days.

Map style change – Both the ski piste overlay and base topo map will be upgraded. Nothing really drastic, I can cite among other changes :

  • Improve mid-zoom (8-11) readibility
  • Reduce the color difference for nordic pistes mapped with the ‘colour’ tag and those without.
  • Add power lines, withpout them, associated cuts in forest land seems odd.
  • Renders single trees, tree rows and hedges.
  • Fix a few glitches on downhill pistes rendering.

 Note for external users

For those using OpenSnowMap tiles in their websites, there is nothing to do. Your users may experience a few tiles missing during database reload, I will do my best to reduce the downtime to a minimum. Those using a proxy-cache to serve the tiles will be warned in advance to have the opportunity to reset their cache in oder to minimize the mosaic effect between old and new tiles created by the new styles deployment.

Update 11 July 2021

The switch is effective for normal tiles, HDPI tiles for the mobile website are deactivated during pre-rendering the base zooms.

piste:difficulty on relations (EN – FR)

As you may have noticed, renders pistes with no difficulty tagged with faint lines, and, if you zoom enough, there is a ? icon on the pistes.

I figured out recently that some mappers add the piste:difficulty tag on route relations for crosscountry or nordic ski trails. So, I first thought, ‘great’, I missed that, let’s make nicer lines and get rid off all the question marks where I can.

But that’s not really helpful, as on about a third of those pistes, the piste:difficulty tag on relation is inconsistent as the one of the member ways. So, unless I’m missing something, I’d rather advise against lazy mapping and rather incite you to map the difficulty on ways.

What do you think ?

Comments are welcome on this diary entry or the tag wiki discussion page.


Vous l’aurez peut-être remarqué, sur les pistes qui n’ont pas le tag piste:difficulty mappé sont rendues avec une ligne plus légère. Si vous zoomez suffisamment, il y a même une icône ? sur la piste.

Récemment, je me suis rendu compte que certains mappeurs mettaient le tag piste:difficulty sur les relations ‘route’ pour le ski de fond. Super, je vais donc pouvoir mettre des lignes plus nette et enlever tout ces points d’interrogation là ou c’est possible.

Mais en fait non. Sur prés d’un tiers de ces pistes, la difficulté renseignée sur les membres n’est pas la même que celle de la relation. Alors à moins que je ne comprenne pas quelque chose, je vous encourage à laisser votre paresse de coté et utiliser le tag piste:difficulty sur les chemins, et non sur les relations.

Qu’en pensez-vous ?

Vous pouvez apporter votre commentaire sur cette entrée de mon  journal ou sur la page de discussion du tag.

OpenSnowMap donation drive winter 2020/2021 ! is around for a few years now. The map tiles are viewed by tens of thousand of visitors each month.

Although not bleeding edge technology, I think it’s a good thing to have it around in the Openstreetmap ecosystem, along with others like Thunderforest outdoors,, and others.

The server has cost of around 1300Euros per year. The budget balance depends from donations for one part, the rest coming from my pocket.

Details on this page shows outstanding donation in 2016, 2017 (sharing work done on the map contours and hillshading were granted by generous gift from mapping companies) and 2019 (sharing the complete map with a heavy user behind a cache). Yet, throughout the years, only a very small amount is also collected from individuals.

I want to help !

For this 2020/2021 winter season, I decided to explicitly ask here for recurring donations in order to sustain the website without relying on an occasional windfall, and also to give you the occasion to show your support.

You can do this with paypal via the donation page or contact me via email found there to do a wire transfer.

You won’t avoid Paypal or your bank fees, nor have a tax refund: we are talking about ski here, OpenSnowMap certainly don’t claims to be an NGO or charity organization of some kind.

What you get ?

Now what do you get that is not already available? First, all my love, the satisfaction to show your support to a map you like, and assist its goal to propose a nice rendering of ski pistes in order to attract new contributors completing the map. But with a new year starting, here are a few resolutions I consider:

  • Discuss with the OSMF the trademark licence for “opensnowmap” name and domain (long overdue)
  • Add a few README and CONTRIBUTING to the github repositories to help people willing to help.
  • If the recurring donation allows it, add a fallback mirror 4TB SSD for the database.
  • And of course voluntarily maintain the service for the years to come.

A word on resources sharing

OpenSnowMap server is rented at Hetzner for 113.88 euros per month.

It serves the map can be seen at, of course, but also on a few other websites.

The piste-only tile overlay is open to all websites and Apps. On the contrary the topo ‘base snow map’ use is restricted to ensure a good quality of service. Its use is granted to a few websites dedicated to winter sports and run by enthusiasts. The only heavy user is, they manage a good exposition to our map while heavily caching the tiles themselves, and supported the server upgrade in 2019.

Discussion is always open to grant access if your project can helps ski mapping in OpenStreetMap awareness from potential contributors and/or technical or financial help to support load beyond 50’000 tiles per day.

Sincerely yours, Yves

New server is being deployed – URL change

Dear users, A generous donation accelerated the deployment of on a more powerful server. No big changes, except a faster rendering and the possibility to serve more tiles. This will help in following the increasing number of requests for ski maps.

Many thanks to the team at !

Part of the map requests are already handled by this new server, so you may experience a longer load time while the tile cache is building up.

If you are using the ski map tiles on your own website, please use the url, tile servingfrom will soon be deprecated. Also, heavy users (> 50’000 tiles per day) are requested to access the tiles via their own cache.

Keep an eye on map changes

Some of you may already use the daily and weekly change view of to check for changes on the ski pistes they mapped.
Today, this view have been improved and now gives more information about the actual change. Is this a way, a relation deleted, a simple node moved? A new processing associated with a detailed legend will help to better understand thechanges and maybe spot errors.

See, yesterday apparently someone seems to have refined a nicely mapped skating ring.

This view coupled with the  button will allow you to find more information about the modified element. It is still a bit frustrating not to be able to check on deleted elements, I will try to add daily and weekly .html change list to allow this.

In practice, each night, the pistes of the OpenStreetMap database at 00:00GMT are compared to the pistes that were there the day and the week before. Geometries are simplified in order not to display to much information.