diff --git a/.gitignore b/.gitignore
index b540ed8..66f4aa9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,4 +5,5 @@ venv
 .venv
 *.pyc
 uv.lock
-.python-version
\ No newline at end of file
+.python-version
+/out
\ No newline at end of file
diff --git a/midas/cli/highlighter.py b/midas/cli/highlighter.py
index 9b24259..b297404 100644
--- a/midas/cli/highlighter.py
+++ b/midas/cli/highlighter.py
@@ -7,6 +7,7 @@ from typing import Generic, Optional, Protocol, TextIO, TypeVar
 import midas.ast.midas as m
 import midas.ast.python as p
 from midas.ast.location import Location
+from midas.checker.diagnostic import Diagnostic
 
 H = TypeVar("H", bound="Highlighter", contravariant=True)
 
@@ -71,6 +72,7 @@ class Highlighter(ABC):
                 openings: list[str] = self.openings.get(pos, [])
                 line_buf += "".join(closings + openings)
                 line_buf += char
+            line_buf += "".join(self.closings.get((lineno, len(line)), []))
             line_buf += "</div></div>"
             lines.append("        " + line_buf)
         lines.extend(
@@ -83,7 +85,7 @@ class Highlighter(ABC):
 
         buf.write("\n".join(lines))
 
-    def wrap(self, node: Locatable, cls: str):
+    def wrap(self, node: Locatable, cls: str, message: Optional[str] = None):
         if node.location is None:
             return
         if node.location.end_lineno is None or node.location.end_col_offset is None:
@@ -95,6 +97,10 @@ class Highlighter(ABC):
         )
         opening: str = f'<span class="{cls}" title="{cls}">'
         closing: str = "</span>"
+        if message is not None:
+            opening = f'<span class="with-msg">{opening}'
+            closing = f'{closing}<span class="message">{message}</span></span>'
+
         self.openings.setdefault(start_pos, []).append(opening)
         self.closings.setdefault(end_pos, []).insert(0, closing)
         if start_pos[0] != end_pos[0]:
@@ -260,3 +266,11 @@ class MidasHighlighter(Highlighter, m.Stmt.Visitor[None], m.Expr.Visitor[None]):
         self.wrap(expr, "type")
         if expr.template is not None:
             expr.template.accept(self)
+
+
+class DiagnosticsHighlighter(Highlighter):
+    EXTRA_CSS_PATH: Optional[Path] = Path(__file__).parent / "hl_diagnostic.css"
+
+    def highlight(self, diagnostics: list[Diagnostic]):
+        for diagnostic in diagnostics:
+            self.wrap(diagnostic, str(diagnostic.type).lower(), diagnostic.message)
diff --git a/midas/cli/hl_diagnostic.css b/midas/cli/hl_diagnostic.css
new file mode 100644
index 0000000..f79bab5
--- /dev/null
+++ b/midas/cli/hl_diagnostic.css
@@ -0,0 +1,32 @@
+span {
+    &.error {
+        --col: 255, 0, 0;
+    }
+    &.warning {
+        --col: 250, 160, 0;
+    }
+    &.info {
+        --col: 150, 190, 250;
+    }
+
+    &.with-msg {
+        position: relative;
+        &:not(:hover) {
+            .message {
+                display: none;
+            }
+        }
+
+        .message {
+            position: absolute;
+            top: calc(100% + 0.2em);
+            left: -.2em;
+            background-color: black;
+            color: white;
+            padding: 0.2em 0.4em;
+            border-radius: .2em;
+            z-index: 10;
+            width: 300%;
+        }
+    }
+}
\ No newline at end of file
diff --git a/midas/cli/main.py b/midas/cli/main.py
index 9119a07..220cca9 100644
--- a/midas/cli/main.py
+++ b/midas/cli/main.py
@@ -13,7 +13,7 @@ from midas.ast.location import Location
 from midas.ast.printer import MidasAstPrinter, PythonAstPrinter
 from midas.checker.checker import Checker
 from midas.checker.diagnostic import Diagnostic
-from midas.cli.highlighter import Highlighter, MidasHighlighter, PythonHighlighter
+from midas.cli.highlighter import DiagnosticsHighlighter, Highlighter, MidasHighlighter, PythonHighlighter
 from midas.lexer.midas import MidasLexer
 from midas.lexer.token import Token, TokenType
 from midas.parser.midas import MidasParser
@@ -28,8 +28,9 @@ def midas():
 
 
 @midas.command()
+@click.option("-l", "--highlight", type=click.File("w"))
 @click.argument("file", type=click.File("r"))
-def compile(file: TextIO):
+def compile(highlight: Optional[TextIO], file: TextIO):
     logging.basicConfig(level=logging.DEBUG)
     source: str = file.read()
     tree: ast.Module = ast.parse(source, filename=file.name)
@@ -50,6 +51,10 @@ def compile(file: TextIO):
             indent=4,
         )
     )
+    if highlight is not None:
+        highlighter = DiagnosticsHighlighter(source)
+        highlighter.highlight(diagnostics)
+        highlighter.dump(highlight)
 
 
 @midas.group()