https://www.apipost.cn/

this is not good.
I don't know what your project is like. If you don't want to use php+mysql, you can use nodejs+mongodb, to save data without building a table. You can build a collection to store data, and you don't have to configure the php environment.
there are many websites that can mock data. But the data is generally pre-defined, regardless of the trouble of writing logic, if you have the skill, you might as well comment out the ajax at the front end and use the written data directly. Setting up a server is not necessarily more troublesome than this.

what you need is a backend cloud? Leancloud, this is a family. The interest has nothing to do with it, so why recommend it? Because I am also using

aggregation: https://www.juhe.cn/
and some other api stores, but forget, you can also use nodejs to read and write files. You don't have to build a database and php,localstorage and indexDB are good. There is also a elasticsearch I think

access database does not need to be installed to read and write directly

do you mean the front and back ends are separated? In fact, the browser itself has local storage, similar to the database I have indexDB and web SQL code and usage, if necessary, you can talk in private. There are many ways to use node or localstorage if you really can't. My own front end suggests using node

mock

postman?. Well, it doesn't seem to match the title. I'm sorry

to implement basic HTTP communication. It's called httpbin.org . If you think the official website is slow, you can build your own docker version, but I don't seem to have ever seen one that can still achieve complete CRUD even when it's ready to use.