diff --git a/poem/CHANGELOG.md b/poem/CHANGELOG.md
index 3fe86b39..567b869c 100644
--- a/poem/CHANGELOG.md
+++ b/poem/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+# [1.2.21] 2022-1-4
+
+- Add test utilities.
+
 # [1.2.20] 2022-1-1
 
 - `RouteMethod` returns `MethodNotAllowedError` error instead of `NotFoundError` when the corresponding method is not found.
diff --git a/poem/Cargo.toml b/poem/Cargo.toml
index 8f84521b..6a517f69 100644
--- a/poem/Cargo.toml
+++ b/poem/Cargo.toml
@@ -34,6 +34,7 @@ opentelemetry = ["libopentelemetry", "opentelemetry-http", "opentelemetry-semant
 prometheus = ["libopentelemetry", "opentelemetry-prometheus", "libprometheus"]
 tempfile = ["libtempfile"]
 csrf = ["cookie", "base64", "libcsrf"]
+test = ["sse", "sse-codec", "tokio-util/compat"]
 
 [dependencies]
 poem-derive = { path = "../poem-derive", version = "1.2.21" }
@@ -84,6 +85,7 @@ sha1 = { version = "0.6.0", optional = true }
 base64 = { version = "0.13.0", optional = true }
 libcsrf = { package = "csrf", version = "0.4.1", optional = true }
 httpdate = { version = "1.0.2", optional = true }
+sse-codec = { version = "0.3.2", optional = true }
 
 # Feature optional dependencies
 anyhow = { version = "1.0.0", optional = true }
diff --git a/poem/src/lib.rs b/poem/src/lib.rs
index 05bff4eb..71cf5da5 100644
--- a/poem/src/lib.rs
+++ b/poem/src/lib.rs
@@ -256,6 +256,9 @@ pub mod middleware;
 #[cfg(feature = "session")]
 #[cfg_attr(docsrs, doc(cfg(feature = "session")))]
 pub mod session;
+#[cfg(feature = "test")]
+#[cfg_attr(docsrs, doc(cfg(feature = "test")))]
+pub mod test;
 pub mod web;
 
 #[doc(inline)]
diff --git a/poem/src/test/client.rs b/poem/src/test/client.rs
new file mode 100644
index 00000000..282b4dd7
--- /dev/null
+++ b/poem/src/test/client.rs
@@ -0,0 +1,90 @@
+use http::{header, header::HeaderName, HeaderMap, HeaderValue, Method};
+
+use crate::{endpoint::BoxEndpoint, test::TestRequestBuilder, Endpoint, Response};
+
+macro_rules! impl_methods {
+    ($($(#[$docs:meta])* ($name:ident, $method:ident)),*) => {
+        $(
+        $(#[$docs])*
+        pub fn $name(&self, uri: impl Into<String>) -> TestRequestBuilder<'_, E> {
+            TestRequestBuilder::new(self, Method::$method, uri.into())
+        }
+        )*
+    };
+}
+
+/// A client for testing.
+///
+/// # Examples
+///
+/// ```
+/// use poem::{handler, test::TestClient, Route};
+///
+/// #[handler]
+/// fn index() {}
+///
+/// let app = Route::new().at("/", index);
+///
+/// let cli = TestClient::new(index);
+///
+/// # tokio::runtime::Runtime::new().unwrap().block_on(async {
+/// cli.get("/").send().await.assert_status_is_ok();
+/// # });
+/// ```
+pub struct TestClient<E = BoxEndpoint<'static, Response>> {
+    pub(crate) ep: E,
+    pub(crate) default_headers: HeaderMap,
+}
+
+impl<E: Endpoint> TestClient<E> {
+    /// Create a new client for the specified endpoint.
+    pub fn new(ep: E) -> Self {
+        Self {
+            ep,
+            default_headers: Default::default(),
+        }
+    }
+
+    /// Sets the default header for each requests.
+    #[must_use]
+    pub fn default_header<K, V>(mut self, key: K, value: V) -> Self
+    where
+        K: TryInto<HeaderName>,
+        V: TryInto<HeaderValue>,
+    {
+        let key = key.try_into().map_err(|_| ()).expect("valid header name");
+        let value = value
+            .try_into()
+            .map_err(|_| ())
+            .expect("valid header value");
+        self.default_headers.append(key, value);
+        self
+    }
+
+    /// Sets the default content type for each requests.
+    #[must_use]
+    pub fn default_content_type(self, content_type: impl AsRef<str>) -> Self {
+        self.default_header(header::CONTENT_TYPE, content_type.as_ref())
+    }
+
+    impl_methods!(
+        /// Create a `GET` request.
+        (get, GET),
+        /// Create a `POST` request.
+        (post, POST),
+        /// Create a `PUT` request.
+        (put, PUT),
+        /// Create a `DELETE` request.
+        (delete, DELETE),
+        /// Create a `HEAD` request.
+        (head, HEAD),
+        /// Create a `OPTIONS` request.
+        (options, OPTIONS),
+        /// Create a `CONNECT` request.
+        (connect, CONNECT),
+        /// Create a `PATCH` request.
+        (patch, PATCH),
+        /// Create a `TRACE` request.
+        (trace, TRACE)
+    );
+}
diff --git a/poem/src/test/json.rs b/poem/src/test/json.rs
new file mode 100644
index 00000000..810b9ebd
--- /dev/null
+++ b/poem/src/test/json.rs
@@ -0,0 +1,217 @@
+use serde::{de::DeserializeOwned, Deserialize, Serialize};
+use serde_json::{Map, Value};
+
+/// A JSON object for testing.
+#[derive(Debug, Deserialize, Serialize, PartialEq, Clone)]
+pub struct TestJson(Value);
+
+impl TestJson {
+    /// Returns a reference the value.
+    #[inline]
+    pub fn value(&self) -> TestJsonValue<'_> {
+        TestJsonValue(&self.0)
+    }
+}
+
+macro_rules! impl_types {
+    ($($(#[$docs:meta])* ($ty:ty, $name:ident, $method:ident)),*) => {
+        $(
+        $(#[$docs])*
+        pub fn $name(&self) -> $ty {
+            self.0.$method().expect(stringify!($name))
+        }
+        )*
+    };
+}
+
+macro_rules! impl_assert_types {
+    ($($(#[$docs:meta])* ($ty:ty, $name:ident, $method:ident)),*) => {
+        $(
+        $(#[$docs])*
+        pub fn $name(&self, value: $ty) {
+            assert_eq!(self.$method(), value);
+        }
+        )*
+    };
+}
+
+macro_rules! impl_array_types {
+    ($($(#[$docs:meta])* ($ty:ty, $name:ident, $method:ident)),*) => {
+        $(
+        $(#[$docs])*
+        pub fn $name(&self) -> Vec<$ty> {
+            self.array().iter().map(|value| value.$method()).collect()
+        }
+        )*
+    };
+}
+
+macro_rules! impl_assert_array_types {
+    ($($(#[$docs:meta])* ($ty:ty, $name:ident, $method:ident)),*) => {
+        $(
+        $(#[$docs])*
+        pub fn $name(&self, values: &[$ty]) {
+            assert_eq!(self.$method(), values);
+        }
+        )*
+    };
+}
+
+/// A JSON value.
+#[derive(Debug, PartialEq, Copy, Clone)]
+pub struct TestJsonValue<'a>(&'a Value);
+
+impl<'a> PartialEq<Value> for TestJsonValue<'a> {
+    fn eq(&self, other: &Value) -> bool {
+        self.0 == other
+    }
+}
+
+impl<'a> TestJsonValue<'a> {
+    impl_types!(
+        /// Returns the `i64` value.
+        (i64, i64, as_i64),
+        /// Returns the `f64` value.
+        (f64, f64, as_f64),
+        /// Returns the `f64` value.
+        (bool, bool, as_bool)
+    );
+
+    impl_array_types!(
+        /// Returns the `i64` array.
+        (i64, i64_array, i64),
+        /// Returns the `i64` array.
+        (f64, f64_array, f64),
+        /// Returns the `i64` array.
+        (bool, bool_array, bool)
+    );
+
+    impl_assert_types!(
+        /// Asserts that value is `integer` and it equals to `value`.
+        (i64, assert_i64, i64),
+        /// Asserts that value is `float` and it equals to `value`.
+        (f64, assert_f64, f64),
+        /// Asserts that value is `boolean` and it equals to `value`.
+        (bool, assert_bool, bool),
+        /// Asserts that value is `string` and it equals to `value`.
+        (&str, assert_string, string)
+    );
+
+    impl_assert_array_types!(
+        /// Asserts that value is `integer` array and it equals to `values`.
+        (i64, assert_i64_array, i64_array),
+        /// Asserts that value is `float` array and it equals to `values`.
+        (f64, assert_f64_array, f64_array),
+        /// Asserts that value is `boolean` array and it equals to `values`.
+        (bool, assert_bool_array, bool_array),
+        /// Asserts that value is `string` array and it equals to `values`.
+        (&str, assert_string_array, string_array)
+    );
+
+    /// Returns the `string` value.
+    pub fn string(&self) -> &'a str {
+        self.0.as_str().expect("string")
+    }
+
+    /// Returns the `string` array.
+    pub fn string_array(&self) -> Vec<&'a str> {
+        self.array().iter().map(|value| value.string()).collect()
+    }
+
+    /// Asserts that the value is an array and return `TestJsonArray`.
+    pub fn array(&self) -> TestJsonArray<'a> {
+        TestJsonArray(self.0.as_array().expect("array"))
+    }
+
+    /// Asserts that the value is an object and return `TestJsonArray`.
+    pub fn object(&self) -> TestJsonObject<'a> {
+        TestJsonObject(self.0.as_object().expect("object"))
+    }
+
+    /// Asserts that the value is an object array and return
+    /// `Vec<TestJsonObject>`.
+    pub fn object_array(&self) -> Vec<TestJsonObject<'a>> {
+        self.array().iter().map(|value| value.object()).collect()
+    }
+
+    /// Asserts that the value is null.
+    pub fn assert_null(&self) {
+        assert!(self.0.is_null())
+    }
+
+    /// Deserialize the value to `T`.
+    pub fn deserialize<T: DeserializeOwned>(&self) -> T {
+        serde_json::from_value(self.0.clone()).expect("valid json")
+    }
+}
+
+/// A JSON array.
+#[derive(Debug, Copy, Clone)]
+pub struct TestJsonArray<'a>(&'a [Value]);
+
+impl<'a, T> PartialEq<T> for TestJsonArray<'a>
+where
+    T: AsRef<[Value]>,
+{
+    fn eq(&self, other: &T) -> bool {
+        self.0 == other.as_ref()
+    }
+}
+
+impl<'a> TestJsonArray<'a> {
+    /// Returns the number of elements in the array.
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    /// Returns true if the array contains no elements.
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    /// Returns the element at index `idx`.
+    pub fn get(&self, idx: usize) -> TestJsonValue<'a> {
+        TestJsonValue(&self.0[idx])
+    }
+
+    /// Returns an iterator over the array.
+    pub fn iter(&self) -> impl Iterator<Item = TestJsonValue<'a>> {
+        self.0.iter().map(TestJsonValue)
+    }
+
+    /// Asserts the array length is equals to `len`.
+    pub fn assert_len(&self, len: usize) {
+        assert_eq!(self.len(), len);
+    }
+}
+
+/// A JSON object.
+#[derive(Debug, Copy, Clone)]
+pub struct TestJsonObject<'a>(&'a Map<String, Value>);
+
+impl<'a> TestJsonObject<'a> {
+    /// Returns the number of elements in the object.
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    /// Returns true if the object contains no elements.
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    /// Returns the element corresponding to the `name`.
+    pub fn get(&self, name: impl AsRef<str>) -> TestJsonValue<'a> {
+        TestJsonValue(&self.0[name.as_ref()])
+    }
+
+    /// Returns an iterator over the object.
+    pub fn iter(&self) -> impl Iterator<Item = (&String, TestJsonValue<'a>)> {
+        self.0.iter().map(|(k, v)| (k, TestJsonValue(v)))
+    }
+
+    /// Asserts the object length is equals to `len`.
+    pub fn assert_len(&self, len: usize) {
+        assert_eq!(self.len(), len);
+    }
+}
diff --git a/poem/src/test/mod.rs b/poem/src/test/mod.rs
new file mode 100644
index 00000000..4181f03c
--- /dev/null
+++ b/poem/src/test/mod.rs
@@ -0,0 +1,11 @@
+//! Test utilities to test your endpoints.
+
+mod client;
+mod json;
+mod request_builder;
+mod response;
+
+pub use client::TestClient;
+pub use json::{TestJson, TestJsonArray, TestJsonObject, TestJsonValue};
+pub use request_builder::TestRequestBuilder;
+pub use response::TestResponse;
diff --git a/poem/src/test/request_builder.rs b/poem/src/test/request_builder.rs
new file mode 100644
index 00000000..93dc6bbd
--- /dev/null
+++ b/poem/src/test/request_builder.rs
@@ -0,0 +1,121 @@
+use http::{header, header::HeaderName, Extensions, HeaderMap, HeaderValue, Method};
+use serde::Serialize;
+
+use crate::{
+    test::{TestClient, TestResponse},
+    Body, Endpoint, Request,
+};
+
+/// A request builder for testing.
+pub struct TestRequestBuilder<'a, E> {
+    cli: &'a TestClient<E>,
+    uri: String,
+    method: Method,
+    query: String,
+    headers: HeaderMap,
+    body: Body,
+    extensions: Extensions,
+}
+
+impl<'a, E> TestRequestBuilder<'a, E>
+where
+    E: Endpoint,
+{
+    pub(crate) fn new(cli: &'a TestClient<E>, method: Method, uri: String) -> Self {
+        Self {
+            cli,
+            uri,
+            method,
+            query: Default::default(),
+            headers: Default::default(),
+            body: Body::empty(),
+            extensions: Default::default(),
+        }
+    }
+
+    /// Sets the query string for this request.
+    #[must_use]
+    pub fn query(self, params: impl Serialize) -> Self {
+        Self {
+            query: serde_urlencoded::to_string(params).expect("valid query params"),
+            ..self
+        }
+    }
+
+    /// Sets the header value for this request.
+    #[must_use]
+    pub fn header<K, V>(mut self, key: K, value: V) -> Self
+    where
+        K: TryInto<HeaderName>,
+        V: TryInto<HeaderValue>,
+    {
+        let key = key.try_into().map_err(|_| ()).expect("valid header name");
+        let value = value
+            .try_into()
+            .map_err(|_| ())
+            .expect("valid header value");
+        self.headers.append(key, value);
+        self
+    }
+
+    /// Sets the content type for this request.
+    #[must_use]
+    pub fn content_type(self, content_type: impl AsRef<str>) -> Self {
+        self.header(header::CONTENT_TYPE, content_type.as_ref())
+    }
+
+    /// Sets the body for this request.
+    #[must_use]
+    pub fn body(self, body: impl Into<Body>) -> Self {
+        Self {
+            body: body.into(),
+            ..self
+        }
+    }
+
+    /// Sets the JSON body for this request.
+    #[must_use]
+    pub fn body_json(self, body: &impl Serialize) -> Self {
+        Self {
+            body: serde_json::to_string(&body).expect("valid json").into(),
+            ..self
+        }
+    }
+
+    fn make_request(self) -> Request {
+        let uri = if self.query.is_empty() {
+            self.uri
+        } else {
+            format!("{}?{}", self.uri, self.query)
+        };
+
+        let mut req = Request::builder()
+            .method(self.method)
+            .uri(uri.parse().expect("valid uri"))
+            .finish();
+        req.headers_mut().extend(self.cli.default_headers.clone());
+        req.headers_mut().extend(self.headers);
+        *req.extensions_mut() = self.extensions;
+        req.set_body(self.body);
+
+        req
+    }
+
+    /// Sets the extension data for this request.
+    #[must_use]
+    pub fn data<T>(mut self, data: T) -> Self
+    where
+        T: Send + Sync + 'static,
+    {
+        self.extensions.insert(data);
+        self
+    }
+
+    /// Send this request to endpoint to get the response.
+    pub async fn send(self) -> TestResponse {
+        let ep = &self.cli.ep;
+        let req = self.make_request();
+        let resp = ep.get_response(req).await;
+        TestResponse::new(resp)
+    }
+}
diff --git a/poem/src/test/response.rs b/poem/src/test/response.rs
new file mode 100644
index 00000000..39430c12
--- /dev/null
+++ b/poem/src/test/response.rs
@@ -0,0 +1,139 @@
+use futures_util::{Stream, StreamExt};
+use http::{header, header::HeaderName, HeaderValue, StatusCode};
+use serde::{de::DeserializeOwned, Serialize};
+use serde_json::Value;
+use tokio_util::compat::TokioAsyncReadCompatExt;
+
+use crate::{test::json::TestJson, web::sse::Event, Body, Response};
+
+/// A response object for testing.
+pub struct TestResponse(Response);
+
+impl TestResponse {
+    pub(crate) fn new(resp: Response) -> Self {
+        Self(resp)
+    }
+
+    /// Consumes this object and returns the [`Response`].
+    pub fn into_inner(self) -> Response {
+        self.0
+    }
+
+    /// Asserts that the status code is equals to `status`.
+    pub fn assert_status(&self, status: StatusCode) {
+        assert_eq!(self.0.status(), status);
+    }
+
+    /// Asserts that the status code is `200 OK`.
+    pub fn assert_status_is_ok(&self) {
+        self.assert_status(StatusCode::OK);
+    }
+
+    /// Asserts that header `key` is equals to `value`.
+    pub fn assert_header<K, V>(&self, key: K, value: V)
+    where
+        K: TryInto<HeaderName>,
+        V: TryInto<HeaderValue>,
+    {
+        let key = key.try_into().map_err(|_| ()).expect("valid header name");
+        let value = value
+            .try_into()
+            .map_err(|_| ())
+            .expect("valid header value");
+
+        let value2 = self
+            .0
+            .headers()
+            .get(&key)
+            .unwrap_or_else(|| panic!("expect header `{}`", key));
+
+        assert_eq!(value2, value);
+    }
+
+    /// Asserts that content type is equals to `content_type`.
+    pub fn assert_content_type(&self, content_type: &str) {
+        self.assert_header(header::CONTENT_TYPE, content_type);
+    }
+
+    /// Consumes this object and return the response body.
+    #[inline]
+    pub fn into_body(self) -> Body {
+        self.0.into_body()
+    }
+
+    /// Asserts that the response body is utf8 string and it equals to `text`.
+    pub async fn assert_text(self, text: impl AsRef<str>) {
+        assert_eq!(
+            self.into_body().into_string().await.expect("expect body"),
+            text.as_ref()
+        );
+    }
+
+    /// Asserts that the response body is bytes and it equals to `bytes`.
+    pub async fn assert_bytes(self, bytes: impl AsRef<[u8]>) {
+        assert_eq!(
+            self.into_body().into_vec().await.expect("expect body"),
+            bytes.as_ref()
+        );
+    }
+
+    /// Asserts that the response body is JSON and it equals to `json`.
+    pub async fn assert_json(self, json: impl Serialize) {
+        assert_eq!(
+            self.into_body()
+                .into_json::<Value>()
+                .await
+                .expect("expect body"),
+            serde_json::to_value(json).expect("valid json")
+        );
+    }
+
+    /// Consumes this object and return the [`TestJson`].
+    pub async fn json(self) -> TestJson {
+        self.into_body()
+            .into_json::<TestJson>()
+            .await
+            .expect("expect body")
+    }
+
+    /// Consumes this object and return the SSE events stream.
+    pub fn sse_stream(self) -> impl Stream<Item = Event> + Send + Unpin + 'static {
+        self.assert_content_type("text/event-stream");
+        sse_codec::decode_stream(self.into_body().into_async_read().compat())
+            .map(|res| {
+                let event = res.expect("valid sse frame");
+                match event {
+                    sse_codec::Event::Message { id, event, data } => Event::Message {
+                        id: id.unwrap_or_default(),
+                        event,
+                        data,
+                    },
+                    sse_codec::Event::Retry { retry } => Event::Retry { retry },
+                }
+            })
+            .boxed()
+    }
+
+    /// Consumes this object and return the SSE events stream which deserialize
+    /// the message data to `T`.
+    pub fn typed_sse_stream<T: DeserializeOwned + 'static>(
+        self,
+    ) -> impl Stream<Item = T> + Send + Unpin + 'static {
+        self.sse_stream()
+            .filter_map(|event| async move {
+                match event {
+                    Event::Message { data, .. } => {
+                        Some(serde_json::from_str::<T>(&data).expect("valid data"))
+                    }
+                    Event::Retry { .. } => None,
+                }
+            })
+            .boxed()
+    }
+
+    /// Consumes this object and return the SSE events stream which deserialize
+    /// the message data to [`TestJson`].
+    pub fn json_sse_stream(self) -> impl Stream<Item = TestJson> + Send + Unpin + 'static {
+        self.typed_sse_stream::<TestJson>()
+    }
+}