There is no size limit, the only limit would be a time limit of 5 minutes.

5 minutes limit of what? I didn't understand.

For GET and POST requests.

That's not really my problem. Could you tell me why this problem is happening in my api? only some routes are not running on the railway. But in Render's hosting service, all routes are working correctly.

Without sharing your errors or issues theres unfortunately nothing I could tell you.

There would not be a limit on individual routes. Railway isn't spinning up serverless functions for each route like a service such as Vercel would. This means Railway doesn't do anything special to specific routes. It just exposes entire services or apps, and those services and apps handle the routes themselves.