diff --git a/TODO.md b/TODO.md
index 5d76eaf..c2bfeed 100644
--- a/TODO.md
+++ b/TODO.md
@@ -7,4 +7,5 @@
 * ✅ Implement CLI
 * ✅ Implement lexer loader that respects aliases
 * ✅ Implement lexer loader by file extension
+* ✅ Add --line-numbers to terminal formatter
 * Implement lexer loader by mime type
\ No newline at end of file
diff --git a/src/formatters/ansi.cr b/src/formatters/ansi.cr
index 16d9e79..e37aa66 100644
--- a/src/formatters/ansi.cr
+++ b/src/formatters/ansi.cr
@@ -2,10 +2,16 @@ require "../formatter"
 
 module Tartrazine
   class Ansi < Formatter
+    property? line_numbers : Bool = false
+
     def format(text : String, lexer : Lexer, theme : Theme) : String
       output = String.build do |outp|
-        lexer.tokenize(text).each do |token|
-          outp << self.colorize(token[:value], token[:type], theme)
+        lexer.group_tokens_in_lines(lexer.tokenize(text)).each_with_index do |line, i|
+          label = line_numbers? ? "#{i + 1}".rjust(4).ljust(5) : ""
+          outp << label
+          line.each do |token|
+            outp << colorize(token[:value], token[:type], theme)
+          end
         end
       end
       output
diff --git a/src/formatters/html.cr b/src/formatters/html.cr
index 40af672..b179531 100644
--- a/src/formatters/html.cr
+++ b/src/formatters/html.cr
@@ -37,7 +37,7 @@ module Tartrazine
     end
 
     def format_text(text : String, lexer : Lexer, theme : Theme) : String
-      lines = group_tokens_in_lines(lexer.tokenize(text))
+      lines = lexer.group_tokens_in_lines(lexer.tokenize(text))
       output = String.build do |outp|
         if surrounding_pre?
           pre_style = wrap_long_lines? ? "style=\"white-space: pre-wrap; word-break: break-word;\"" : ""
@@ -101,28 +101,5 @@ module Tartrazine
     def highlighted?(line : Int) : Bool
       highlight_lines.any?(&.includes?(line))
     end
-
-    def group_tokens_in_lines(tokens : Array(Token)) : Array(Array(Token))
-      split_tokens = [] of Token
-      tokens.each do |token|
-        if token[:value].includes?("\n")
-          values = token[:value].split("\n")
-          values.each_with_index do |value, index|
-            value += "\n" if index < values.size - 1
-            split_tokens << {type: token[:type], value: value}
-          end
-        else
-          split_tokens << token
-        end
-      end
-      lines = [Array(Token).new]
-      split_tokens.each do |token|
-        lines.last << token
-        if token[:value].includes?("\n")
-          lines << Array(Token).new
-        end
-      end
-      lines
-    end
   end
 end
diff --git a/src/lexer.cr b/src/lexer.cr
index 9635cc2..63e5b7d 100644
--- a/src/lexer.cr
+++ b/src/lexer.cr
@@ -124,6 +124,30 @@ module Tartrazine
       result
     end
 
+    # Group tokens into lines, splitting them when a newline is found
+    def group_tokens_in_lines(tokens : Array(Token)) : Array(Array(Token))
+      split_tokens = [] of Token
+      tokens.each do |token|
+        if token[:value].includes?("\n")
+          values = token[:value].split("\n")
+          values.each_with_index do |value, index|
+            value += "\n" if index < values.size - 1
+            split_tokens << {type: token[:type], value: value}
+          end
+        else
+          split_tokens << token
+        end
+      end
+      lines = [Array(Token).new]
+      split_tokens.each do |token|
+        lines.last << token
+        if token[:value].includes?("\n")
+          lines << Array(Token).new
+        end
+      end
+      lines
+    end
+
     # ameba:disable Metrics/CyclomaticComplexity
     def self.from_xml(xml : String) : Lexer
       l = Lexer.new
diff --git a/src/main.cr b/src/main.cr
index 3dc6439..414ced9 100644
--- a/src/main.cr
+++ b/src/main.cr
@@ -6,9 +6,11 @@ tartrazine: a syntax highlighting tool
 
 Usage:
   tartrazine (-h, --help)
-  tartrazine FILE -f html [-t theme][--standalone][--line-numbers][-l lexer] [-o output]
+  tartrazine FILE -f html [-t theme][--standalone][--line-numbers]
+                          [-l lexer][-o output]
   tartrazine -f html -t theme --css
-  tartrazine FILE -f terminal [-t theme][-l lexer][-o output]
+  tartrazine FILE -f terminal [-t theme][-l lexer][--line-numbers]
+                              [-o output]
   tartrazine FILE -f json [-o output]
   tartrazine --list-themes
   tartrazine --list-lexers
@@ -61,6 +63,7 @@ if options["-f"]
     formatter.line_numbers = options["--line-numbers"] != nil
   when "terminal"
     formatter = Tartrazine::Ansi.new
+    formatter.line_numbers = options["--line-numbers"] != nil
   when "json"
     formatter = Tartrazine::Json.new
   else