diff --git a/src/nfa.rs b/src/nfa.rs
index 17c1282..e15a1be 100644
--- a/src/nfa.rs
+++ b/src/nfa.rs
@@ -315,7 +315,7 @@ impl NfaBuilder {
     }
 
     fn group(mut self, start: StateId, end: StateId) -> Self {
-        self.capture_groups.push(CaptureGroup { start, end });
+        self.capture_groups.insert(0, CaptureGroup { start, end });
         self
     }
 
@@ -358,19 +358,19 @@ mod tests {
 
     #[test]
     fn test_concatenation() {
-        let nfa = NfaBuilder::default()
+        let expected = NfaBuilder::default()
             .transition(0, TransitionKind::Character('h'), 1)
             .transition(1, TransitionKind::Epsilon, 2)
             .transition(2, TransitionKind::Character('i'), 3)
             .build();
-        let expected = to_nfa("hi");
+        let nfa = to_nfa("hi");
 
-        assert_eq!(nfa, expected);
+        assert_eq!(expected, nfa);
     }
 
     #[test]
     fn test_alternation() {
-        let nfa = NfaBuilder::default()
+        let expected = NfaBuilder::default()
             .transition(0, TransitionKind::Epsilon, 1)
             .transition(0, TransitionKind::Epsilon, 3)
             .transition(1, TransitionKind::Character('a'), 2)
@@ -378,50 +378,50 @@ mod tests {
             .transition(3, TransitionKind::Character('b'), 4)
             .transition(4, TransitionKind::Epsilon, 5)
             .build();
-        let expected = to_nfa("a|b");
+        let nfa = to_nfa("a|b");
 
-        assert_eq!(nfa, expected);
+        assert_eq!(expected, nfa);
     }
 
     #[test]
     fn test_range_excat() {
-        let nfa = NfaBuilder::default()
+        let expected = NfaBuilder::default()
             .transition(0, TransitionKind::Character('e'), 1)
             .transition(1, TransitionKind::Epsilon, 2)
             .transition(2, TransitionKind::Character('e'), 3)
             .transition(3, TransitionKind::Epsilon, 4)
             .transition(4, TransitionKind::Character('e'), 5)
             .build();
-        let expected = to_nfa("e{3}");
+        let nfa = to_nfa("e{3}");
 
-        assert_eq!(nfa, expected);
+        assert_eq!(expected, nfa);
     }
 
     #[test]
     fn test_range_between() {
-        let nfa = NfaBuilder::default()
+        let expected = NfaBuilder::default()
             .transition(0, TransitionKind::Character('e'), 1)
             .transition(1, TransitionKind::Epsilon, 2)
             .transition(2, TransitionKind::Character('e'), 3)
             .transition(2, TransitionKind::Epsilon, 3)
             .build();
-        let expected = to_nfa("e{1,2}");
+        let nfa = to_nfa("e{1,2}");
 
-        assert_eq!(nfa, expected);
+        assert_eq!(expected, nfa);
     }
 
     #[test]
     fn test_range_minimum() {
-        let nfa = NfaBuilder::default()
+        let expected = NfaBuilder::default()
             .transition(0, TransitionKind::Character('e'), 1)
             .transition(1, TransitionKind::Epsilon, 2)
             .transition(2, TransitionKind::Character('e'), 3)
             .transition(3, TransitionKind::Epsilon, 1)
             .transition(3, TransitionKind::Epsilon, 4)
             .build();
-        let expected = to_nfa("e{2,}");
+        let nfa = to_nfa("e{2,}");
 
-        assert_eq!(nfa, expected);
+        assert_eq!(expected, nfa);
     }
 
     #[test]
@@ -454,4 +454,17 @@ mod tests {
 
         assert_eq!(eclosure, expected);
     }
+
+    #[test]
+    fn test_capture_group_order() {
+        let nfa = to_nfa("a(b(c)(d))(e)");
+        let expected = vec![
+            CaptureGroup { start: 2, end: 7 },
+            CaptureGroup { start: 4, end: 5 },
+            CaptureGroup { start: 6, end: 7 },
+            CaptureGroup { start: 8, end: 9 },
+        ];
+
+        assert_eq!(nfa.capture_groups, expected);
+    }
 }
diff --git a/src/regex.rs b/src/regex.rs
index 4ec9c05..bee7d72 100644
--- a/src/regex.rs
+++ b/src/regex.rs
@@ -144,23 +144,14 @@ impl<'a> Regex {
                 continue;
             }
 
-            captures.insert(0, (Some(start), end)); // full match
-
             let captures = captures
                 .into_iter()
-                .flat_map(|(index, (start, end))| {
-                    start
-                        .zip(end)
-                        .map(|(start, end)| (index, Match::new(start, end, &input[start..end])))
-                })
+                .chain([(0, (Some(start), end))])
+                .flat_map(|(index, (start, end))| Some(index).zip(self.new_mach(input, start, end)))
                 .collect();
             let named_captures = named_captures
                 .into_iter()
-                .flat_map(|(name, (start, end))| {
-                    start
-                        .zip(end)
-                        .map(|(start, end)| (name, Match::new(start, end, &input[start..end])))
-                })
+                .flat_map(|(name, (start, end))| Some(name).zip(self.new_mach(input, start, end)))
                 .collect();
 
             let capture = Capture {
@@ -186,6 +177,17 @@ impl<'a> Regex {
         states.iter().any(|s| self.nfa.is_accepting(*s))
     }
 
+    fn new_mach(
+        &self,
+        input: &'a str,
+        start: Option<usize>,
+        end: Option<usize>,
+    ) -> Option<Match<'a>> {
+        start
+            .zip(end)
+            .map(|(start, end)| Match::new(start, end, &input[start..end]))
+    }
+
     fn update_captures(
         &self,
         captures: &mut HashMap<usize, (Option<usize>, Option<usize>)>,
@@ -195,48 +197,66 @@ impl<'a> Regex {
     ) {
         for state in states {
             if let Some(groups) = self.start_capture.get(state) {
-                self.update_capture_starts(captures, named_captures, groups, position);
+                for group in groups {
+                    self.update_capture_start(captures, named_captures, group, position);
+                }
             }
             if let Some(groups) = self.end_capture.get(state) {
-                self.update_capture_ends(captures, named_captures, groups, position);
+                for group in groups {
+                    self.update_capture_end(captures, named_captures, group, position);
+                }
             }
         }
     }
 
-    fn update_capture_starts(
+    fn update_capture_start(
         &self,
         captures: &mut HashMap<usize, (Option<usize>, Option<usize>)>,
         named_captures: &mut HashMap<String, (Option<usize>, Option<usize>)>,
-        groups: &[CaptureKind],
+        group: &CaptureKind,
         position: usize,
     ) {
-        for group in groups {
-            match group {
-                CaptureKind::Indexed(index) => {
-                    captures.entry(*index + 1).or_default().0 = Some(position)
-                }
-                CaptureKind::Named(name) => {
-                    named_captures.entry(name.to_owned()).or_default().0 = Some(position)
-                }
+        match group {
+            CaptureKind::Indexed(index) => {
+                captures
+                    .entry(*index + 1)
+                    .and_modify(|(start, end)| {
+                        if end.is_none() {
+                            *start = Some(position)
+                        }
+                    })
+                    .or_insert((Some(position), None));
+            }
+            CaptureKind::Named(name) => {
+                named_captures
+                    .entry(name.to_owned())
+                    .and_modify(|(start, end)| {
+                        if end.is_none() {
+                            *start = Some(position)
+                        }
+                    })
+                    .or_insert((Some(position), None));
             }
         }
     }
 
-    fn update_capture_ends(
+    fn update_capture_end(
         &self,
         captures: &mut HashMap<usize, (Option<usize>, Option<usize>)>,
         named_captures: &mut HashMap<String, (Option<usize>, Option<usize>)>,
-        groups: &[CaptureKind],
+        group: &CaptureKind,
         position: usize,
     ) {
-        for group in groups {
-            match group {
-                CaptureKind::Indexed(index) => {
-                    captures.entry(*index + 1).or_default().1 = Some(position)
-                }
-                CaptureKind::Named(name) => {
-                    named_captures.entry(name.to_owned()).or_default().1 = Some(position)
-                }
+        match group {
+            CaptureKind::Indexed(index) => {
+                captures
+                    .entry(*index + 1)
+                    .and_modify(|(_, end)| *end = Some(position));
+            }
+            CaptureKind::Named(name) => {
+                named_captures
+                    .entry(name.to_owned())
+                    .and_modify(|(_, end)| *end = Some(position));
             }
         }
     }
@@ -334,7 +354,12 @@ impl<'a> Match<'a> {
 
 #[cfg(test)]
 mod test {
-    use crate::regex::{Match, Regex};
+    use std::collections::HashMap;
+
+    use crate::{
+        regex::{Match, Regex},
+        Capture,
+    };
 
     #[test]
     fn test_simple_match() {
@@ -432,6 +457,24 @@ mod test {
         assert_eq!(matches.get_name("minute"), Some(&Match::new(3, 5, "30")));
     }
 
+    // #[test]
+    // fn test_repeated_group() {
+    //     let regex = Regex::new(r#"(hi)+(ah)+"#).unwrap();
+    //     let matches = regex.captures("hihiah").unwrap();
+    //     let expected = Capture {
+    //         captures: vec![
+    //             (0, Match::new(0, 6, "hihiah")),
+    //             (1, Match::new(2, 4, "hi")),
+    //             (2, Match::new(4, 6, "ah")),
+    //         ]
+    //         .into_iter()
+    //         .collect(),
+    //         named_captures: HashMap::new(),
+    //     };
+    //
+    //     assert_eq!(matches, expected);
+    // }
+
     #[test]
     fn test_find() {
         let regex = Regex::new(r#"wh(at|o|y)"#).unwrap();
diff --git a/src/wasm.rs b/src/wasm.rs
index e47bd9a..88858a4 100644
--- a/src/wasm.rs
+++ b/src/wasm.rs
@@ -74,7 +74,7 @@ impl RegexGroup {
 }
 
 #[wasm_bindgen]
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct RegexCapture {
     groups: Vec<RegexGroup>,
 }
@@ -125,32 +125,31 @@ fn get_char_index(input: &str) -> HashMap<usize, usize> {
         .collect()
 }
 
-// #[cfg(test)]
-// mod tests {
-//     use super::{RegexEngine, RegexGroup};
-//
-//     #[test]
-//     fn test_unicode_range() {
-//         let regex = RegexEngine::new(r#"ここ"#);
-//         let matches = regex.find_all("ここでここで");
-//
-//         assert_eq!(
-//             matches,
-//             vec![
-//                 RegexGroup { start: 0, end: 2 },
-//                 RegexGroup { start: 3, end: 5 },
-//             ]
-//         );
-//
-//         let regex = RegexEngine::new(r#"日本語"#);
-//         let matches = regex.find_all("これは日本語のテストです。日本語");
-//
-//         assert_eq!(
-//             matches,
-//             vec![
-//                 RegexGroup { start: 3, end: 6 },
-//                 RegexGroup { start: 13, end: 16 },
-//             ]
-//         );
-//     }
-// }
+#[cfg(test)]
+mod tests {
+    use super::{RegexCapture, RegexEngine, RegexGroup};
+
+    #[test]
+    fn test_unicode_range() {
+        let regex = RegexEngine::new(r#"ここ"#);
+        let matches = regex.captures_all("ここでここで");
+        let expected = vec![
+            RegexCapture {
+                groups: vec![RegexGroup {
+                    name: "0".to_string(),
+                    start: 0,
+                    end: 2,
+                }],
+            },
+            RegexCapture {
+                groups: vec![RegexGroup {
+                    name: "0".to_string(),
+                    start: 3,
+                    end: 5,
+                }],
+            },
+        ];
+
+        assert_eq!(matches, expected);
+    }
+}
diff --git a/web/src/App.tsx b/web/src/App.tsx
index 919cdc7..2d6d904 100644
--- a/web/src/App.tsx
+++ b/web/src/App.tsx
@@ -4,7 +4,7 @@ import Navbar from "./components/Navbar";
 import ExpressionsPopup from "./components/ExpressionsPopup";
 import { RiQuestionFill } from "react-icons/ri";
 import { RegexEngine, RegexCapture } from "regex-potata";
-import { graphFromRegex } from "./utils/viz";
+import { graphFromRegex } from "./utils/graphiz";
 import TestInput from "./components/TestInput";
 import Footer from "./components/Footer";
 import RegexInput from "./components/RegexInput";
diff --git a/web/src/components/ExpressionsPopup.tsx b/web/src/components/ExpressionsPopup.tsx
index 74b63a6..c2d57aa 100644
--- a/web/src/components/ExpressionsPopup.tsx
+++ b/web/src/components/ExpressionsPopup.tsx
@@ -3,11 +3,11 @@ import { useRef } from "react";
 import Snippet from "./Snippet";
 
 const expressions = [
-  { desc: "Basic regex", pat: ["foo", "(bar)", "foo|bar", "fo."] },
+  { desc: "Basic regex", pat: ["foo", "(bar)", "foo|bar"] },
   { desc: "Quantifiers", pat: ["+", "*", "?", "{x}", "{x,y}", "{x,}"] },
   {
     desc: "Character class",
-    pat: ["a-z]", "[^x]", "\\d", "\\D", "\\w", "\\W", "\\s", "\\S"],
+    pat: [".", "[a-z]", "[^x]", "\\d", "\\D", "\\w", "\\W", "\\s", "\\S"],
   },
   { desc: "Capture groups", pat: ["(foo)", "(:?bar)", "(?<name>foo)"] },
 ];
diff --git a/web/src/utils/extensions.ts b/web/src/utils/extensions.ts
index 6d9425d..e1d89cd 100644
--- a/web/src/utils/extensions.ts
+++ b/web/src/utils/extensions.ts
@@ -20,7 +20,7 @@ function getMatchHighlight(captures: RegexCapture[]) {
   const decorationBuilder = new RangeSetBuilder<Decoration>();
 
   for (let i = 0; i < captures.length; i++) {
-    const groups = captures[i].groups();
+    const groups = captures[i].groups().sort((a, b) => a.start - b.start);
 
     decorationBuilder.add(
       groups[0].start,
@@ -37,7 +37,7 @@ function getMatchHighlight(captures: RegexCapture[]) {
         groups[j].end,
         decoration(
           `color: #0f172a; background-color: ${
-            palette[i + (j % palette.length)]
+            palette[(i + j) % palette.length]
           }`
         )
       );
diff --git a/web/src/utils/viz.ts b/web/src/utils/graphiz.ts
similarity index 100%
rename from web/src/utils/viz.ts
rename to web/src/utils/graphiz.ts