diff --git a/lib/outputcomponents.php b/lib/outputcomponents.php
index ff5428b9978..8ed6e1ec986 100644
--- a/lib/outputcomponents.php
+++ b/lib/outputcomponents.php
@@ -4916,6 +4916,14 @@ class progress_bar implements renderable, templatable {
         }
     }
 
+    /**
+     * Getter for ID
+     * @return string id
+     */
+    public function get_id() : string {
+        return $this->html_id;
+    }
+
     /**
      * Create a new progress bar, this function will output html.
      *
@@ -4925,9 +4933,6 @@ class progress_bar implements renderable, templatable {
         global $OUTPUT;
 
         $this->time_start = microtime(true);
-        if (CLI_SCRIPT) {
-            return; // Temporary solution for cli scripts.
-        }
 
         flush();
         echo $OUTPUT->render($this);
@@ -4943,15 +4948,13 @@ class progress_bar implements renderable, templatable {
      * @throws coding_exception
      */
     private function _update($percent, $msg) {
+        global $OUTPUT;
+
         if (empty($this->time_start)) {
             throw new coding_exception('You must call create() (or use the $autostart ' .
                     'argument to the constructor) before you try updating the progress bar.');
         }
 
-        if (CLI_SCRIPT) {
-            return; // Temporary solution for cli scripts.
-        }
-
         $estimate = $this->estimate($percent);
 
         if ($estimate === null) {
@@ -4965,16 +4968,15 @@ class progress_bar implements renderable, templatable {
             return;
         }
 
-        $estimatemsg = null;
-        if (is_numeric($estimate)) {
-            $estimatemsg = get_string('secondsleft', 'moodle', round($estimate, 2));
+        $estimatemsg = '';
+        if ($estimate != 0 && is_numeric($estimate)) {
+            $estimatemsg = format_time(round($estimate));
         }
 
-        $this->percent = round($percent, 2);
+        $this->percent = $percent;
         $this->lastupdate = microtime(true);
 
-        echo html_writer::script(js_writer::function_call('updateProgressBar',
-            array($this->html_id, $this->percent, $msg, $estimatemsg)));
+        echo $OUTPUT->render_progress_bar_update($this->html_id, sprintf("%.1f", $this->percent), $msg, $estimatemsg);
         flush();
     }
 
diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index abfb60339dc..222eaf33b69 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -4776,6 +4776,22 @@ EOD;
         return $this->render_from_template('core/progress_bar', $data);
     }
 
+    /**
+     * Renders an update to a progress bar.
+     *
+     * Note: This does not cleanly map to a renderable class and should
+     * never be used directly.
+     *
+     * @param  string $id
+     * @param  float $percent
+     * @param  string $msg Message
+     * @param  string $estimate time remaining message
+     * @return string ascii fragment
+     */
+    public function render_progress_bar_update(string $id, float $percent, string $msg, string $estimate) : string {
+        return html_writer::script(js_writer::function_call('updateProgressBar', [$id, $percent, $msg, $estimate]));
+    }
+
     /**
      * Renders element for a toggle-all checkbox.
      *
@@ -4800,6 +4816,12 @@ EOD;
  */
 class core_renderer_cli extends core_renderer {
 
+    /**
+     * @var array $progressmaximums stores the largest percentage for a progress bar.
+     * @return string ascii fragment
+     */
+    private $progressmaximums = [];
+
     /**
      * Returns the page header.
      *
@@ -4844,6 +4866,99 @@ class core_renderer_cli extends core_renderer {
         return $this->render_check_result($result);
     }
 
+    /**
+     * Renders a progress bar.
+     *
+     * Do not use $OUTPUT->render($bar), instead use progress_bar::create().
+     *
+     * @param  progress_bar $bar The bar.
+     * @return string ascii fragment
+     */
+    public function render_progress_bar(progress_bar $bar) {
+        global $CFG;
+
+        $size = 55; // The width of the progress bar in chars.
+        $ascii = "\n";
+
+        if (stream_isatty(STDOUT)) {
+            require_once($CFG->libdir.'/clilib.php');
+
+            $ascii .= "[" . str_repeat(' ', $size) . "] 0% \n";
+            return cli_ansi_format($ascii);
+        }
+
+        $this->progressmaximums[$bar->get_id()] = 0;
+        $ascii .= '[';
+        return $ascii;
+    }
+
+    /**
+     * Renders an update to a progress bar.
+     *
+     * Note: This does not cleanly map to a renderable class and should
+     * never be used directly.
+     *
+     * @param  string $id
+     * @param  float $percent
+     * @param  string $msg Message
+     * @param  string $estimate time remaining message
+     * @return string ascii fragment
+     */
+    public function render_progress_bar_update(string $id, float $percent, string $msg, string $estimate) : string {
+        $size = 55; // The width of the progress bar in chars.
+        $ascii = '';
+
+        // If we are rendering to a terminal then we can safely use ansii codes
+        // to move the cursor and redraw the complete progress bar each time
+        // it is updated.
+        if (stream_isatty(STDOUT)) {
+            $colour = $percent == 100 ? 'green' : 'blue';
+
+            $done = $percent * $size * 0.01;
+            $whole = floor($done);
+            $bar = "<colour:$colour>";
+            $bar .= str_repeat('█', $whole);
+
+            if ($whole < $size) {
+                // By using unicode chars for partial blocks we can have higher
+                // precision progress bar.
+                $fraction = floor(($done - $whole) * 8);
+                $bar .= core_text::substr(' ▏▎▍▌▋▊▉', $fraction, 1);
+
+                // Fill the rest of the empty bar.
+                $bar .= str_repeat(' ', $size - $whole - 1);
+            }
+
+            $bar .= '<colour:normal>';
+
+            if ($estimate) {
+                $estimate = "- $estimate";
+            }
+
+            $ascii .= '<cursor:up>';
+            $ascii .= '<cursor:up>';
+            $ascii .= sprintf("[$bar] %3.1f%% %-22s\n", $percent, $estimate);
+            $ascii .= sprintf("%-80s\n", $msg);
+            if ($percent == 100) {
+                $ascii .= "\n";
+            }
+            return cli_ansi_format($ascii);
+        }
+
+        // If we are not rendering to a tty, ie when piped to another command
+        // or on windows we need to progressively render the progress bar
+        // which can only ever go forwards.
+        $done = round($percent * $size * 0.01);
+        $delta = max(0, $done - $this->progressmaximums[$id]);
+        $this->progressmaximums[$id] += $delta;
+
+        $ascii .= str_repeat('#', $delta);
+        if ($percent >= 100) {
+            $ascii .= sprintf("] %3.1f%%\n$msg\n", $percent);
+        }
+        return $ascii;
+    }
+
     /**
      * Returns a template fragment representing a Heading.
      *