REST几乎总是更快。SOAP的主要优点是它提供了一种机制，可以让服务向客户端描述自己，并宣传它们的存在。

REST轻量级得多，几乎可以使用任何工具实现，从而降低带宽，缩短学习曲线。然而，客户端必须知道要发送什么以及期望发送什么。

通常，当您向外界发布复杂或可能更改的API时，SOAP将更有用。除此之外，REST通常是更好的选择。

REST没有WSDL (Web描述语言)接口定义。 REST基于HTTP，但SOAP可以基于任何传输协议，如HTTP、FTP、SMTP、JMS等。

REST是一种体系结构。 REST将给出人类可读的结果。 REST是非状态的。 REST服务很容易被缓存。

SOAP是一种协议。它可以运行在JMS、FTP和HTTP之上。

REST vs. SOAP Web Services I am seeing a lot of new web services are implemented using a REST style architecture these days rather than a SOAP one. Lets step back a second and explain what REST is. What is a REST web service? The acronym REST stands for representational state transfer, and this basically means that each unique URL is a representation of some object. You can get the contents of that object using an HTTP GET, to delete it, you then might use a POST, PUT, or DELETE to modify the object (in practice most of the services use a POST for this). Who's using REST? All of Yahoo's web services use REST, including Flickr and Delicious. APIs use it, pubsub, bloglines, Technorati, and both eBay, and Amazon have web services for both REST and SOAP. Who's using SOAP? Google seams to be consistent in implementing their web services to use SOAP, with the exception of Blogger, which uses XML-RPC. You will find SOAP web services in lots of enterprise software as well. REST vs. SOAP As you may have noticed the companies I mentioned that are using REST APIs haven't been around for very long, and their APIs came out this year mostly. So REST is definitely the trendy way to create a web service, if creating web services could ever be trendy (lets face it you use soap to wash, and you rest when your tired). The main advantages of REST web services are: Lightweight - not a lot of extra XML markup Human Readable Results Easy to build - no toolkits required. SOAP also has some advantages: Easy to consume - sometimes Rigid - type checking, adheres to a contract Development tools For consuming web services, its sometimes a toss up between which is easier. For instance Google's AdWords web service is really hard to consume (in ColdFusion anyway), it uses SOAP headers, and a number of other things that make it kind of difficult. On the converse, Amazon's REST web service can sometimes be tricky to parse because it can be highly nested, and the result schema can vary quite a bit based on what you search for. Whichever architecture you choose make sure its easy for developers to access it, and well documented.

Freitag, P.(2005)。“REST vs SOAP Web服务”。检索自http://www.petefreitag.com/item/431.cfm, 2010年6月13日

SOAP

简单对象访问协议(SOAP)是一种标准的XML语言，定义了消息体系结构和消息格式。Web服务使用它。它包含操作的描述。

WSDL是一种基于xml的语言，用于描述Web服务以及如何访问它们。它将运行在SMTP, HTTP, FTP等。它需要中间件支持和定义良好的机制来定义WSDL+XSD和WS-Policy等服务。 SOAP将返回基于XML的数据

REST

具象状态传输(RESTful) web服务。它们是第二代Web服务。

基于rest的web服务通过HTTP而不是基于soap的服务进行通信，并且不需要XML消息或WSDL服务api定义。对于REST中间件不需要，只需要HTTP支持。它是一个WADL标准，REST可以返回XML、纯文本、JSON、HTML等。

SOAP Web服务:

如果您的应用程序需要有保证的可靠性和安全性级别，那么SOAP将提供额外的标准来确保这种类型的操作。 如果双方(服务提供者和服务使用者)必须就交换格式达成一致，那么SOAP将为这种类型的交互提供严格的规范。

RestWeb服务:

完全无状态操作:用于无状态的CRUD(创建、读取、更新和删除)操作。 缓存情况:如果信息需要缓存。

REST在大多数情况下更容易使用，也更灵活。与SOAP不同，REST不必使用XML来提供响应。我们可以找到基于rest的Web服务，这些服务以命令分隔值(CSV)、JavaScript对象符号(JSON)和真正简单联合(RSS)格式输出数据。

我们可以以一种易于在应用程序所需的语言中解析的形式获得所需的输出。REST更高效(使用更小的消息格式)、更快，并且在设计理念上更接近其他Web技术。

SOAP web服务总是执行POST操作，而使用REST，您可以选择特定的HTTP方法，如GET、POST、PUT和DELETE。

例如:要使用SOAP获取一个项目，您应该创建一个请求XML，但是在REST的情况下，您可以在URL本身中指定项目id。

休息vs.肥皂

SOAP:

SOAP是运行在TCP/UDP/SMTP上的简单对象访问协议。 SOAP以XML格式读取和写入请求响应消息。 SOAP使用接口来定义服务。 SOAP更安全，因为它有自己的安全性和定义良好的标准。 SOAP遵循RPC和文档风格来定义web服务。 SOAP使用SOAP- ui作为客户端工具进行测试。

REST

► REST is representational state transfer that uses underlying HTTP protocols. ► REST is stateless. ► REST is an architectural style that is used to describe and define web services. ► REST can read and write request response messages in JSON/XML/Plain HTML. ► REST uses URI for each resource that is used in web service.A resource can be image text method etc. ► REST uses set of verbs, like HTTP's GET, POST, PUT, DELETE. ► REST is easy to develop and easy to manage as compared to SOAP UI. ► REST has light-weight client tools or plugins that can easily be integrated inside a browser. ► REST services are cacheable.

REST stands for representational state transfer whereas SOAP stands for Simple Object Access Protocol. SOAP defines its own security where as REST inherits security from the underlying transport. SOAP does not support error handling, but REST has built-in error handling. REST is lightweight and does not require XML parsing. REST can be consumed by any client, even a web browser with Ajax and JavaScript. REST consumes less bandwidth, it does not require a SOAP header for every message. REST is useful over any protocol which provide a URI. Ignore point 5 for REST as mentioned below in the picture.

REST和SOAP的区别: