diff --git a/biome.jsonc b/biome.jsonc
new file mode 100644
index 0000000..1b6e9be
--- /dev/null
+++ b/biome.jsonc
@@ -0,0 +1,57 @@
+{
+  "$schema": "https://biomejs.dev/schemas/1.9.4/schema.json",
+  "vcs": {
+    "enabled": false,
+    "clientKind": "git",
+    "useIgnoreFile": false
+  },
+  "files": {
+    "ignoreUnknown": false,
+    "ignore": ["./src/paraglide"],
+    "include": ["./src/**"]
+  },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space"
+  },
+  "organizeImports": {
+    "enabled": true
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "recommended": true
+    }
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "double",
+      "semicolons": "asNeeded",
+      "arrowParentheses": "asNeeded"
+    }
+  },
+  "overrides": [
+    {
+      "include": ["*.astro"],
+      "linter": {
+        "rules": {
+          "style": {
+            "useConst": "off",
+            "useImportType": "off"
+          }
+        }
+      }
+    },
+    {
+      "include": ["*.svelte"],
+      "linter": {
+        "rules": {
+          "style": {
+            "useConst": "off",
+            "useImportType": "off"
+          }
+        }
+      }
+    }
+  ]
+}
diff --git a/flake.lock b/flake.lock
index 938b1df..6047a9b 100644
--- a/flake.lock
+++ b/flake.lock
@@ -16,26 +16,9 @@
         "type": "github"
       }
     },
-    "nixpkgs-unstable": {
-      "locked": {
-        "lastModified": 1751271578,
-        "narHash": "sha256-P/SQmKDu06x8yv7i0s8bvnnuJYkxVGBWLWHaU+tt4YY=",
-        "owner": "nixos",
-        "repo": "nixpkgs",
-        "rev": "3016b4b15d13f3089db8a41ef937b13a9e33a8df",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nixos",
-        "ref": "nixos-unstable",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs",
-        "nixpkgs-unstable": "nixpkgs-unstable"
+        "nixpkgs": "nixpkgs"
       }
     }
   },
diff --git a/flake.nix b/flake.nix
index 5d813e4..01b5833 100644
--- a/flake.nix
+++ b/flake.nix
@@ -25,6 +25,7 @@
             pnpm
           ] ++ [
             nodePackages.prettier
+            biome
           ];
 
           shellHook = ''
diff --git a/package.json b/package.json
index 75295ed..f84ae45 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,9 @@
     "astro": "astro",
     "type-check": "astro check",
     "postinstall": "paraglide-js compile --project ./project.inlang --outdir ./src/paraglide",
-    "format": "prettier --write \"./src/**/*.{js,mjs,ts,astro,svelte,css,md,json}\"",
+    "format": "biome format --write .",
+    "lint": "biome lint --write .",
+    "lint:fix": "biome check --write .",
     "watch-messages": "paraglide-js compile --watch --project ./project.inlang --outdir ./src/paraglide"
   },
   "dependencies": {