diff --git a/README.md b/README.md
index 07eadd9..0080d4f 100644
--- a/README.md
+++ b/README.md
@@ -230,7 +230,7 @@ that it loads properly.
 [signature option]: https://godoc.org/willnorris.com/go/imageproxy#hdr-Signature
 
 Some simple code samples for generating signatures in various languages can be
-found in [URL Signing](https://github.com/willnorris/imageproxy/wiki/URL-signing).
+found in [docs/url-signing.md](/docs/url-signing.md).
 
 If both a whiltelist and signatureKey are specified, requests can match either.
 In other words, requests that match one of the allowed hosts don't necessarily
diff --git a/docs/url-signing.md b/docs/url-signing.md
new file mode 100644
index 0000000..19bcaa1
--- /dev/null
+++ b/docs/url-signing.md
@@ -0,0 +1,117 @@
+# How to generate signed requests
+
+## Go
+
+main.go:
+```go
+package main
+
+import (
+        "os"
+        "fmt"
+        "crypto/hmac"
+        "crypto/sha256"
+        "encoding/base64"
+)
+
+func main() {
+        mac := hmac.New(sha256.New, []byte(os.Args[1]))
+        mac.Write([]byte(os.Args[2]))
+        want := mac.Sum(nil)
+        fmt.Println("result: ",base64.URLEncoding.EncodeToString(want))
+}
+```
+
+```shell
+$ go run main.go "test" "https://www.google.fr/images/srpr/logo11w.png"
+result:  RYifAJRfbhsitJeOrDNxWURCCkPsVR4ihCPXNv-ePbA=
+```
+
+## OpenSSL
+
+```shell
+$ echo -n "https://www.google.fr/images/srpr/logo11w.png" | openssl dgst -sha256 -hmac "test" -binary|base64| tr '/+' '_-'
+RYifAJRfbhsitJeOrDNxWURCCkPsVR4ihCPXNv-ePbA=
+```
+
+## Java
+
+```java
+import org.apache.commons.codec.binary.Base64;
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+class EncodeUrl {
+
+  public static String encode(String key, String data) throws Exception {
+    Mac sha256_HMAC = Mac.getInstance("HmacSHA256");
+    SecretKeySpec secret_key = new SecretKeySpec(key.getBytes(), "HmacSHA256");
+    sha256_HMAC.init(secret_key);
+
+    return Base64.encodeBase64URLSafeString(sha256_HMAC.doFinal(data.getBytes()));
+  }
+
+  public static void main(String [] args) throws Exception {
+    System.out.println(encode(args[0], args[1]));
+  }
+
+}
+```
+
+```shell
+$ java -cp commons-codec-1.10.jar:. EncodeUrl test https://www.google.fr/images/srpr/logo11w.png
+RYifAJRfbhsitJeOrDNxWURCCkPsVR4ihCPXNv-ePbA
+```
+
+## Ruby
+
+```ruby
+require 'openssl'
+require 'base64'
+
+key = "test"
+data = "https://www.google.fr/images/srpr/logo11w.png"
+puts Base64.urlsafe_encode64(OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), key, data)).strip()
+```
+
+```shell
+% ruby sign.rb
+RYifAJRfbhsitJeOrDNxWURCCkPsVR4ihCPXNv-ePbA=
+```
+
+## Python
+
+```python
+import hmac
+import hashlib
+import base64
+
+key = 'secret key'
+data = 'https://octodex.github.com/images/codercat.jpg'
+print base64.urlsafe_b64encode(hmac.new(key, msg=data, digestmod=hashlib.sha256).digest()) 
+```
+
+## JavaScript
+
+```javascript
+import crypto from 'crypto';
+import URLSafeBase64 from 'urlsafe-base64';
+
+let key = 'secret key';
+let data = 'https://octodex.github.com/images/codercat.jpg';
+console.log(URLSafeBase64.encode(crypto.createHmac('sha256', key).update(data).digest()));
+```
+
+## PHP
+
+````php
+<?php
+$key = 'test';
+$data = "https://www.google.fr/images/srpr/logo11w.png";
+echo strtr(base64_encode(hash_hmac('sha256', $data, $key, 1)), '/+' , '_-');
+````
+
+````shell
+$ php ex.php
+RYifAJRfbhsitJeOrDNxWURCCkPsVR4ihCPXNv-ePbA=
+````
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