diff --git a/lib/twine/cli.rb b/lib/twine/cli.rb
index dd5e086..19b7b6a 100644
--- a/lib/twine/cli.rb
+++ b/lib/twine/cli.rb
@@ -33,6 +33,8 @@ module Twine
         opts.separator ''
         opts.separator 'generate-report -- Generates a report containing data about your strings. For example, it will tell you if you have any duplicate strings or if any of your strings are missing tags. In addition, it will tell you how many strings you have and how many of those strings have been translated into each language.'
         opts.separator ''
+        opts.separator 'validate-strings-file -- Validates that the given strings file is parseable, contains no duplicates, and that every string has a tag. Exits with a non-zero exit code if those criteria are not met.'
+        opts.separator ''
         opts.separator 'General Options:'
         opts.separator ''
         opts.on('-l', '--lang LANGUAGES', Array, 'The language code(s) to use for the specified action.') do |langs|
@@ -97,6 +99,7 @@ module Twine
         opts.separator '> twine generate-loc-drop strings.txt LocDrop5.zip --tags FT,FB --format android --lang de,en,en-GB,ja,ko'
         opts.separator '> twine consume-loc-drop strings.txt LocDrop5.zip'
         opts.separator '> twine generate-report strings.txt'
+        opts.separator '> twine validate-strings-file strings.txt'
       end
       parser.parse! @args
 
diff --git a/lib/twine/runner.rb b/lib/twine/runner.rb
index f811b7a..6c90fc9 100644
--- a/lib/twine/runner.rb
+++ b/lib/twine/runner.rb
@@ -3,7 +3,7 @@ require 'tmpdir'
 Twine::Plugin.new # Initialize plugins first in Runner.
 
 module Twine
-  VALID_COMMANDS = ['generate-string-file', 'generate-all-string-files', 'consume-string-file', 'consume-all-string-files', 'generate-loc-drop', 'consume-loc-drop', 'generate-report']
+  VALID_COMMANDS = ['generate-string-file', 'generate-all-string-files', 'consume-string-file', 'consume-all-string-files', 'generate-loc-drop', 'consume-loc-drop', 'generate-report', 'validate-strings-file']
 
   class Runner
     def initialize(args)
@@ -50,6 +50,8 @@ module Twine
         consume_loc_drop
       when 'generate-report'
         generate_report
+      when 'validate-strings-file'
+        validate_strings_file
       end
     end
 
@@ -260,6 +262,43 @@ module Twine
       end
     end
 
+    def validate_strings_file
+      total_strings = 0
+      all_keys = Set.new
+      duplicate_keys = Set.new
+      keys_without_tags = Set.new
+
+      @strings.sections.each do |section|
+        section.rows.each do |row|
+          total_strings += 1
+
+          if all_keys.include? row.key
+            duplicate_keys.add(row.key)
+          else
+            all_keys.add(row.key)
+          end
+
+          if row.tags == nil || row.tags.length == 0
+            keys_without_tags.add(row.key)
+          end
+        end
+      end
+
+      if duplicate_keys.length > 0
+        error_body = duplicate_keys.to_a.join("\n  ")
+        raise Twine::Error.new "Found duplicate string key(s):\n  #{error_body}"
+      end
+
+      if keys_without_tags.length == total_strings
+        raise Twine::Error.new "None of your strings have tags."
+      elsif keys_without_tags.length > 0
+        error_body = keys_without_tags.to_a.join("\n  ")
+        raise Twine::Error.new "Found strings(s) without tags:\n  #{error_body}"
+      end
+
+      puts "#{@options[:strings_file]} is valid."
+    end
+
     def determine_language_given_path(path)
       code = File.basename(path, File.extname(path))
       if !@strings.language_codes.include? code