# Changes in D3 5.0
[Released March 22, 2018.](https://github.com/d3/d3/releases/tag/v5.0.0)
*This document covers only major changes. For minor and patch changes, please see the [release notes](https://github.com/d3/d3/releases).*
D3 5.0 introduces only a few non-backwards-compatible changes.
D3 now uses [Promises](https://developer.mozilla.org/docs/Web/JavaScript/Guide/Using_promises) instead of asynchronous callbacks to load data. Promises simplify the structure of asynchronous code, especially in modern browsers that support [async and await](https://javascript.info/async-await). (See this [introduction to promises](https://observablehq.com/@observablehq/introduction-to-promises) on [Observable](https://observablehq.com).) For example, to load a CSV file in v4, you might say:
```js
d3.csv("file.csv", function(error, data) {
if (error) throw error;
console.log(data);
});
```
In v5, using promises:
```js
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