Change the LearnDash Mark Complete Button Text and CSS Classes

To change the LearnDash Mark Complete button text without code, go to LearnDash LMS > Settings > Advanced, open the Custom Labels section and fill in the Mark Complete (Button) field. To change it in code, filter learndash_get_label for the button_mark_complete key. To add your own CSS classes or an ID to the button, form or timer, filter learndash_mark_complete_form_atts. Neither approach touches templates, so both survive LearnDash updates.

This snippet covers all three, plus the matching Mark Incomplete button, and explains why you should add classes rather than try to replace the default ones.

Checked against the LearnDash 4.18.0.1 source (includes/course/ld-course-progress.php and includes/class-ld-custom-label.php). LearnDash 5.2.3 is the current release as of October 2026; its changelog lists no change to these filters, but check them on staging after any major update.

Where the button comes from

Lessons and topics render the button through learndash_mark_complete( $post, $atts ). Both the LD30 and Legacy templates call it. The function returns an empty string when the learner cannot complete the step yet (no access, incomplete quizzes or previous steps, and similar), so a missing button is a progression issue, not a label issue.

When it does render, the output is a small form:

The button label comes from LearnDash_Custom_Label::get_label( 'button_mark_complete' ), which reads the learndash_settings_custom_labels option and falls back to the translated string "Mark Complete". If the step is an external event that does not require attendance, LearnDash uses the Skip Event label instead.

Option 1: change the label in settings

1. Go to LearnDash LMS > Settings and open the Advanced tab.
2. Find the Custom Labels section.
3. Enter your text in Mark Complete (Button), for example "Complete and continue".
4. Optionally set Mark Incomplete (Button) so the undo action matches.
5. Save.

This is the right choice for a single-language site. The value is global: every lesson and topic uses it.

Option 2: change the label in code

Use the filter when the label must be translatable, differ per language, or differ per course. The filter runs for every custom label, so check the key first.

<?php
/**
 * Change the LearnDash Mark Complete and Mark Incomplete button labels.
 * Not run on a live site; test on staging first.
 */
function aiol_mark_complete_label( $label, $key ) {
	if ( 'button_mark_complete' === $key ) {
		return esc_html__( 'Complete and continue', 'aiol-snippets' );
	}
	if ( 'button_mark_incomplete' === $key ) {
		return esc_html__( 'Mark as not done', 'aiol-snippets' );
	}
	return $label;
}
add_filter( 'learndash_get_label', 'aiol_mark_complete_label', 10, 2 );

Put it in a small site plugin or your child theme's functions.php. Return escaped, translatable strings, as LearnDash's own defaults do. A filter value overrides whatever is saved in the Custom Labels screen, so tell site admins that the settings field no longer applies.

For a per-course label, check the current course inside the same callback, for example with learndash_get_course_id( get_the_ID() ), and return a different string for the courses that need it.

Option 3: add CSS classes and IDs

learndash_mark_complete_form_atts (since 3.0.0) receives the attributes array and the lesson or topic WP_Post. Whatever you put in class is appended after the default class, and id is added as given. LearnDash escapes both with esc_attr().

<?php
/**
 * Add theme classes to the LearnDash Mark Complete form, button and timer.
 * Not run on a live site; test on staging first.
 */
function aiol_mark_complete_atts( $atts, $post ) {
	$atts = is_array( $atts ) ? $atts : array();

	$atts['form']['class']   = 'aiol-complete-form';
	$atts['button']['class'] = 'btn btn-primary aiol-complete-btn';
	$atts['timer']['class']  = 'aiol-complete-timer';

	// Different styling for topics.
	if ( $post instanceof WP_Post && 'sfwd-topic' === $post->post_type ) {
		$atts['button']['class'] .= ' aiol-complete-btn--topic';
	}

	return $atts;
}
add_filter( 'learndash_mark_complete_form_atts', 'aiol_mark_complete_atts', 10, 2 );

The Mark Incomplete form has its own filter, learndash_mark_incomplete_form_atts, with the same array shape. Its button keeps both learndash_mark_incomplete_button and learndash_mark_complete_button, so style it with the incomplete class if the two need to look different.

Why you cannot remove the default classes

LearnDash always prepends sfwd-mark-complete and learndash_mark_complete_button; the filter only adds to them. That is deliberate. Front-end scripts find the button by those classes:

• The forced-time countdown points at input.learndash_mark_complete_button to enable the button when the timer ends.
• Video progression selects form.sfwd-mark-complete input.learndash_mark_complete_button to enable or auto-submit the form when the video finishes.
• LD30 inline colour styles and the LearnDash customizer settings target the same classes.

If you strip them, for example by rewriting the HTML through learndash_mark_complete or learndash_mark_complete_form_fields, timed and video lessons can stop unlocking. Override the styles in CSS with your added classes instead.

Styling example

.learndash-wrapper .aiol-complete-btn {
	border-radius: 6px;
	font-weight: 600;
	text-transform: none;
}
.learndash-wrapper .aiol-complete-btn:disabled {
	opacity: 0.5;
	cursor: not-allowed;
}

Keep a visible disabled state: on timed lessons LearnDash renders the button with disabled until the countdown finishes, and learners need to see why it does not respond.

Testing checklist

• A lesson with no timer or video: label and classes appear, and the step completes.
• A lesson with a forced timer: the button starts disabled and enables at zero.
• A lesson with video progression: the button appears or auto-submits after the video.
• A completed step: if Mark Incomplete Enabled is switched on in the global course settings, the undo button shows your label.
• Focus mode and the standard LD30 layout, since they wrap the button differently.

If the button does not render at all, look at progression settings, not these filters. Related reading: our LearnDash guide, the wider WordPress LMS development guide, and the matching snippet to change the LearnDash certificate button text.

How we can help

If your course flow needs more than a label change, such as custom completion rules, redirects or a redesigned lesson footer, our LMS plugin development team builds it as an update-safe plugin. See our LearnDash services or contact us.