Hi all,
I’m preparing a study to be carried out with Chinese participants. We use Heroku. However, the app seems to be inaccessible from mainland China. We have conducted studies using Heroku  in China before and did not experience this issue.
Googling suggests that there might be issues related to China’s firewall when using Heroku. Has anyone else experience this issue? Does anyone have suggestions for alternatives to Heroku with servers situated in mainland China (this should solve the issue)? 
Thanks a lot!
Moritz

Hi,
Heroku is not banned but blocked in China. It is sometimes recognized as a security threat because of the end random codes in the end of session/room-wide link, even in FB. You may try to customize the session link so it looks more serious, i.e., give an room name and have a room link. NO AD, I noticed this company that can help with Heroku difficulties in China. I'm not sure about their rate.
https://www.21cloudbox.com/solutions/how-to-speed-up-heroku-in-china.html

Thanks a lot for these suggestions!

Hi All,
I wanted to follow up on this conversation. My Chinese student is trying to conduct an experiment in China but the participant links cannot be opened, even if we created a link. Any suggestion? Is heroku available in China?
Best,
Gergely

We weren't able to figure out a solution that involves Heroku. We're now working with a Chinese company that recruits students as participants and also hosts our experiment on their own platform.

I see thank you, I think I know which company you refer to. I will seek similar solution.

It is a pity that heroku is not working in China anymore, wondering if there could be some solution, like setting up a different server for otree in China.

We are able to access our app in China if we give our apps  custom domains and routed through cloudflare. However if we used xxx.herokuapp.com it doesn't work 

Kendo

Hello! @Moritz and @GergelyH, I have a similar issue and would like to follow up this question. Could you please share which company you worked with to host your experiment instead of using Heroku? Other suggestions and recommendations are also welcomed. 

Best,
Na

Just set up your own Linux server with nginx+oTree (or have your lab manager do it for you).

We used this company: https://www.yanzhonglab.com/account/login?callback=https%3A%2F%2Fwww.yanzhonglab.com%2Fresearcher%2F

Thank you both @gr0ssmann and @Moritz for your suggestions.

In late fall last year, one of our clients similarly faced accessibility issues with their Heroku App in China, primarily due to the country's internet regulations and the global cloud infrastructure used by Heroku. Seeking a solution, we turned to 21YunBox (mentioned above #2), a service recommended for bridging the gap between international cloud platforms and China's unique internet environment.

21YunBox performed a thorough analysis of our app, identifying resources that were slow to load or blocked within China, including images, CSS files, JavaScripts, ect, ect. Their service then optimized these elements to ensure fast loading and accessibility without compromising the app's global performance. To evaluate the improvements, we accessed the app via a specialized URL provided by 21YunBox, which showcased significantly reduced load times—from previously blocked statuses to an impressive 100-150 ms reach time in mainland China.

Since our implementation in mid-October, despite initial minor hiccups, our client's web app has been as accessible and functional in China as it is globally.

https://app.21cloudbox.com/subscribe/

Hope this helps! Good luck ‌👍‌

I just wanted to second the reply from 'kendo' for other people with the same problem: buying a custom domain (~10 USD) through Cloudflare and linking it to our Heroku app solved the issue in no time and was very easy and straightforward. Both Heroku and Cloudflare offer accessible tutorials for the process.

A quick google search gives you websites that let you test the availability in China to see quickly that the default Heroku domain is blocked while custom Cloudflare domains work like a charm.

Very happy with this easy solution that does not rely on external service companies.