diff --git a/editor/src/keyboard_input.rs b/editor/src/keyboard_input.rs
index 99410d28c7..df01638c0d 100644
--- a/editor/src/keyboard_input.rs
+++ b/editor/src/keyboard_input.rs
@@ -1,6 +1,6 @@
 use winit::event::{ElementState, ModifiersState, VirtualKeyCode};
 use crate::tea::model::{Model};
-use crate::tea::update::{move_caret_left, move_caret_right};
+use crate::tea::update::{move_caret_left, move_caret_right, move_caret_down, move_caret_up};
 
 pub fn handle_keydown(
     elem_state: ElementState,
@@ -21,7 +21,9 @@ pub fn handle_keydown(
             model.selection_opt = new_selection_opt;
         },
         Up => {
-            todo!("arrow up");
+            let (new_caret_pos, new_selection_opt) = move_caret_up(model.caret_pos, model.selection_opt, modifiers.shift(), &model.lines);
+            model.caret_pos = new_caret_pos;
+            model.selection_opt = new_selection_opt;
         },
         Right => {
             let (new_caret_pos, new_selection_opt) = move_caret_right(model.caret_pos, model.selection_opt, modifiers.shift(), &model.lines);
@@ -29,7 +31,9 @@ pub fn handle_keydown(
             model.selection_opt = new_selection_opt;
         },
         Down => {
-            todo!("arrow down");
+            let (new_caret_pos, new_selection_opt) = move_caret_down(model.caret_pos, model.selection_opt, modifiers.shift(), &model.lines);
+            model.caret_pos = new_caret_pos;
+            model.selection_opt = new_selection_opt;
         },
         Copy => {
             todo!("copy");
diff --git a/editor/src/tea/model.rs b/editor/src/tea/model.rs
index e4488f4c3a..9670588ceb 100644
--- a/editor/src/tea/model.rs
+++ b/editor/src/tea/model.rs
@@ -1,3 +1,6 @@
+
+use std::cmp::{Ordering};
+
 #[derive(Debug)]
 pub struct Model {
     pub lines: Vec<String>,
@@ -25,6 +28,26 @@ pub struct Position {
     pub column: usize
 }
 
+impl Ord for Position {
+    fn cmp(&self, other: &Self) -> Ordering {
+        (self.line, self.column).cmp(&(other.line, other.column))
+    }
+}
+
+impl PartialOrd for Position {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl PartialEq for Position {
+    fn eq(&self, other: &Self) -> bool {
+        (self.line, self.column) == (other.line, other.column)
+    }
+}
+
+impl Eq for Position { }
+
 #[derive(Debug, Copy, Clone)]
 pub struct RawSelection {
     pub start_pos: Position,
diff --git a/editor/src/tea/update.rs b/editor/src/tea/update.rs
index 84283135d2..8e5fa92be2 100644
--- a/editor/src/tea/update.rs
+++ b/editor/src/tea/update.rs
@@ -1,6 +1,7 @@
 
 use crate::tea::model::{Position, RawSelection};
 use crate::text::{is_newline};
+use std::cmp::{min, max};
 
 pub fn move_caret_left(old_caret_pos: Position, old_selection_opt: Option<RawSelection>, shift_pressed: bool, lines: &[String]) -> (Position, Option<RawSelection>) {
     let old_line_nr = old_caret_pos.line;
@@ -19,6 +20,11 @@ pub fn move_caret_left(old_caret_pos: Position, old_selection_opt: Option<RawSel
             (old_line_nr, old_col_nr - 1)
         };
 
+    let new_caret_pos = Position {
+        line: line_nr,
+        column: col_nr
+    };
+
     let new_selection_opt = 
         if shift_pressed {
             if let Some(old_selection) = old_selection_opt {
@@ -62,10 +68,7 @@ pub fn move_caret_left(old_caret_pos: Position, old_selection_opt: Option<RawSel
 
 
     (
-        Position {
-            line: line_nr,
-            column: col_nr
-        },
+        new_caret_pos,
         new_selection_opt
     )
 }
@@ -95,6 +98,11 @@ pub fn move_caret_right(old_caret_pos: Position, old_selection_opt: Option<RawSe
             (0, 0) // this should never happen, should this method return Result?
         };
 
+    let new_caret_pos = Position {
+            line: line_nr,
+            column: col_nr
+    };
+
     let new_selection_opt = 
         if shift_pressed {
             if let Some(old_selection) = old_selection_opt {
@@ -137,10 +145,136 @@ pub fn move_caret_right(old_caret_pos: Position, old_selection_opt: Option<RawSe
         };
 
     (
-        Position {
+        new_caret_pos,
+        new_selection_opt
+    )
+}
+
+pub fn move_caret_up(old_caret_pos: Position, old_selection_opt: Option<RawSelection>, shift_pressed: bool, lines: &[String]) -> (Position, Option<RawSelection>) {
+    let old_line_nr = old_caret_pos.line;
+    let old_col_nr = old_caret_pos.column;
+
+    let (line_nr, col_nr) =
+        if old_line_nr == 0 {
+            (old_line_nr, old_col_nr)
+        } else if let Some(prev_line) = lines.get(old_line_nr - 1) {
+            if prev_line.len() < old_col_nr {
+                (old_line_nr - 1, prev_line.len() - 1)
+            } else {
+                (old_line_nr - 1, old_col_nr)
+            }
+        } else {
+            (0, 0) // this should never happen, should this method return Result?
+        };
+
+    let new_caret_pos = Position {
             line: line_nr,
             column: col_nr
-        },
+    };
+
+    let new_selection_opt = 
+        if shift_pressed {
+            if let Some(old_selection) = old_selection_opt {
+                Some(
+                    RawSelection {
+                        start_pos:
+                            new_caret_pos
+                        ,
+                        end_pos:
+                            old_selection.end_pos
+                        ,
+                    }
+                )
+            } else if !(old_line_nr == line_nr && old_col_nr == col_nr){
+                    Some(
+                        RawSelection {
+                            start_pos:
+                                min(old_caret_pos, new_caret_pos)
+                            ,
+                            end_pos:
+                                max(old_caret_pos, new_caret_pos)
+                            ,
+                        }
+                    )
+            } else {
+                None
+            }
+            
+        } else {
+            None
+        };
+    
+    (
+        new_caret_pos,
+        new_selection_opt
+    )
+}
+
+pub fn move_caret_down(old_caret_pos: Position, old_selection_opt: Option<RawSelection>, shift_pressed: bool, lines: &[String]) -> (Position, Option<RawSelection>) {
+    let old_line_nr = old_caret_pos.line;
+    let old_col_nr = old_caret_pos.column;
+
+    let (line_nr, col_nr) =
+        if old_line_nr + 1 >= lines.len() {
+            (old_line_nr, old_col_nr)
+        } else if let Some(next_line) = lines.get(old_line_nr + 1) {
+            if next_line.len() < old_col_nr {
+                if let Some(last_char) = next_line.chars().last() {
+                    if is_newline(&last_char) {
+                        (old_line_nr + 1, next_line.len() - 1)
+                    } else {
+                        (old_line_nr + 1, next_line.len())
+                    }
+                } else {
+                    (old_line_nr + 1, 0)
+                }
+                
+            } else {
+                (old_line_nr + 1, old_col_nr)
+            }
+        } else {
+            (0, 0) // this should never happen, should this method return Result?
+        };
+
+    let new_caret_pos = Position {
+        line: line_nr,
+        column: col_nr
+    };
+
+    let new_selection_opt = 
+        if shift_pressed {
+            if let Some(old_selection) = old_selection_opt {
+                Some(
+                    RawSelection {
+                        start_pos:
+                            old_selection.start_pos
+                        ,
+                        end_pos:
+                            new_caret_pos
+                        ,
+                    }
+                )
+            } else if !(old_line_nr == line_nr && old_col_nr == col_nr){
+                    Some(
+                        RawSelection {
+                            start_pos:
+                                min(old_caret_pos, new_caret_pos)
+                            ,
+                            end_pos:
+                                max(old_caret_pos, new_caret_pos)
+                            ,
+                        }
+                    )
+            } else {
+                None
+            }
+            
+        } else {
+            None
+        };
+
+    (
+        new_caret_pos,
         new_selection_opt
     )
 }
\ No newline at end of file