diff --git a/README.md b/README.md
index 67c7d61..65c33c8 100644
--- a/README.md
+++ b/README.md
@@ -6,10 +6,11 @@ Devolve un link para descargalo.
 
 ## Execución
 ```
-UPLOADS="/tmp/uploads/" PORT=4000 cargo run
+UPLOADS="/tmp/uploads/" BASE_URL="http://127.0.0.1" PORT=4000 cargo run
 ```
-As variables de entorno UPLOADS e PORT son opcionais tendo como valores por defecto:
+As variables de entorno UPLOADS, BASE_URL e PORT son opcionais tendo como valores por defecto:
 - UPLOADS = "uploads/"
+- BASE_URL = "http://127.0.0.1"
 - PORT = 3000
 
 ## Funcionamento
diff --git a/src/lib.rs b/src/lib.rs
index c82a04a..0309527 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -26,3 +26,14 @@ pub fn env_listen_port() -> u16 {
         None => 3000,
     }
 }
+
+// le a variable de entorno BASE_URL para configurar o porto de escoita
+// por defecto: http://localhost:3000
+pub fn env_base_url() -> String {
+    let port = env_listen_port();
+
+    match env::var_os("BASE_URL") {
+        Some(val) => format!("{}:{}", val.into_string().unwrap(), port),
+        None => format!("{}:{}", "http://localhost", port),
+    }
+}
diff --git a/src/vistas/root.rs b/src/vistas/root.rs
index 9731009..c942dd4 100644
--- a/src/vistas/root.rs
+++ b/src/vistas/root.rs
@@ -1,16 +1,18 @@
 use axum::response::{Html, IntoResponse, Response};
+use crate::lib::env_base_url;
 
 // basic handler that responds with a static string
 pub async fn basic() -> Response {
-    Html(
+    let url = env_base_url();
+    let html = format!(
         "<pre>
 SH4R.IN
 =======
 
 HTTP POST files here:
-curl -F'file=@yourfile.png' https://sh4r.in
+curl -F'file=@yourfile.png' {}
 You can also POST remote URLs:
-curl -F'url=http://example.com/image.jpg' https://sh4r.in
+curl -F'url=http://example.com/image.jpg' {}
 
 File URLs are valid for aproximately 5 days.
 
@@ -34,11 +36,11 @@ and the originating IP address blocked from further uploads.
 UPLOAD DIRECTLY
 ---------------
 </pre>
-<form action=\"https://sh4r.in\" method=\"POST\" enctype=\"multipart/form-data\">
+<form action=\"{}\" method=\"POST\" enctype=\"multipart/form-data\">
     <input class=\"form-control\" type=\"file\" name=\"file\">
     <input class=\"form-control\" type=\"submit\" value=\"send\">
 </form>
 ",
-    )
-    .into_response()
+    url, url, url);
+    Html(html).into_response()
 }
diff --git a/src/vistas/upload.rs b/src/vistas/upload.rs
index a5f1b30..06ff85f 100644
--- a/src/vistas/upload.rs
+++ b/src/vistas/upload.rs
@@ -1,4 +1,4 @@
-use crate::lib::{randstr, env_uploads_dir};
+use crate::lib::{randstr, env_uploads_dir, env_base_url};
 use axum::{
     extract::Multipart,
     response::{IntoResponse, Response},
@@ -28,7 +28,7 @@ pub async fn upload(mut multipart: Multipart) -> Response {
         let mut file = File::create(dest).await.expect("error creando arquivo");
         file.write_all(&data).await.expect("error gardando contido");
 
-        link = format!("https://sh4r.in/f/{}", fillo);
+        link = format!("{}/f/{}", env_base_url(), fillo);
     }
 
     link.into_response()