Title: Blocks CSS: CSS Editor for Gutenberg Blocks Author: Hardeep Asrani Published: February 14, 2019 Last modified: April 1, 2026 --- Search plugins ![](https://ps.w.org/blocks-css/assets/banner-772x250.jpg?rev=2030330) ![](https://ps.w.org/blocks-css/assets/icon-256x256.jpg?rev=2030330) # Blocks CSS: CSS Editor for Gutenberg Blocks By [Hardeep Asrani](https://profiles.wordpress.org/hardeepasrani/) [Download](https://downloads.wordpress.org/plugin/blocks-css.3.1.8.zip) * [Details](https://twd.wordpress.org/plugins/blocks-css/#description) * [Reviews](https://twd.wordpress.org/plugins/blocks-css/#reviews) * [Development](https://twd.wordpress.org/plugins/blocks-css/#developers) [Support](https://wordpress.org/support/plugin/blocks-css/) ## Description Blocks CSS allows you add custom CSS to your Blocks straight from the Block Editor( Gutenberg). It adds a syntax-highlighted CSS Editor where you can add additional CSS to your Gutenberg Blocks to style them the way you want. All the code and sources for this plugin are publicly available as part of https:// github.com/Codeinwp/otter-blocks. ## Screenshots * [[ * CSS Editor * [[ * CSS Editor ## Blocks This plugin provides 5 blocks. * Text A rich text element with tag selection. * Icon An inline SVG icon from the Lucide icon set. * Link An anchor element with link picker and rich text. * Box A generic wrapper element with tag selection and inner blocks. Supports details and summary tags for native disclosure widgets. * Image A simple image element. Set via media library or direct URL. ## Reviews ![](https://secure.gravatar.com/avatar/2e30329ab3220e0cf929fe14c6efe89bed6c64d148c584e805618d4425862c04? s=60&d=retro&r=g) ### 󠀁[Indispensable!](https://wordpress.org/support/topic/indispensable-272/)󠁿 [maltmann](https://profiles.wordpress.org/maltmann/) February 8, 2026 1 reply Works like a charm on any of my recent WP projects. [EDIT]I need to change my review. On some setups, I get two CSS editors shown in the “Custom CSS” attribute panel, and only contents of the second instance are getting saved.Problem:Two CodeMirror editors are displayed in the Custom CSS panel of the Blocks CSS plugin instead of one. Both editors are located in the same container. Assumed Root Cause:WordPress enables React StrictMode by default in the Block Editor. React StrictMode runs useEffect hooks twice to detect potential side effects. Analysis:The Blocks CSS plugin initializes CodeMirror in a useEffect hook.Since this useEffect doesn’t have a cleanup function that checks whether CodeMirror is already initialized, wp.CodeMirror() is called again on every mount cycle. With StrictMode enabled, this means: twice on the same DOM element. Probable Solution:The useEffect hook should implement a cleanup function that prevents CodeMirror from being initialized multiple times on the same element. Side Notes:This only happens in some of my setups. I couldn’t figure out any possibly conflicting theme, plugin or code snippet. So I assume it might be something like a timing issue. Conclusion:I won’t change the 5-star rating, because despite of this problem the plugin does its job. And I know how to handle this issue by a simple CSS rule to hide all Block CSS CodeMirrors except the last one:#o-css-editor .CodeMirror: not(:last-child) { display: none;} ![](https://secure.gravatar.com/avatar/6cbd96106c76dfd85e755f1aba9c463817d1b9d5dd74bb64b84dad2b458a790c? s=60&d=retro&r=g) ### 󠀁[Отличный плагин](https://wordpress.org/support/topic/%d0%be%d1%82%d0%bb%d0%b8%d1%87%d0%bd%d1%8b%d0%b9-%d0%bf%d0%bb%d0%b0%d0%b3%d0%b8%d0%bd-991/)󠁿 [Сергей](https://profiles.wordpress.org/serzh82/) November 20, 2025 1 reply Отличный плагин ![](https://secure.gravatar.com/avatar/ff57a8df8c1ffea97f5c0992bed6943b19a831dbc8b3a0f9153dc4421fa1c4cc? s=60&d=retro&r=g) ### 󠀁[Моя оценка: пять звезд](https://wordpress.org/support/topic/%d0%bc%d0%be%d1%8f-%d0%be%d1%86%d0%b5%d0%bd%d0%ba%d0%b0-%d0%bf%d1%8f%d1%82%d1%8c-%d0%b7%d0%b2%d0%b5%d0%b7%d0%b4/)󠁿 [shooter604](https://profiles.wordpress.org/shooter604/) November 14, 2025 1 reply Очень классные возможности! Пользуюсь постоянно! ![](https://secure.gravatar.com/avatar/5a04f5d680efd2cb46cc23d68d1e4d7c94f7e4e910dd0b60c54ebd63861e1785? s=60&d=retro&r=g) ### 󠀁[The Other Review Titles Say It All](https://wordpress.org/support/topic/the-other-review-titles-say-it-all/)󠁿 [someguy42](https://profiles.wordpress.org/someguy42/) July 24, 2024 1 reply “Essential, Useful Tool, Completes the Block Editor, Should be part of the core,” The one thing they don’t mention is how quick and genuinely concerned the support is. ![](https://secure.gravatar.com/avatar/fc490c401adf61289262192824d444a5f47939eb723b3ccc8ce7c73065cb7c0f? s=60&d=retro&r=g) ### 󠀁[Simple and great plugin!](https://wordpress.org/support/topic/simple-and-great-plugin-36/)󠁿 [Andreslav](https://profiles.wordpress.org/andreslav/) October 4, 2023 1 reply Does exactly what I need it to do. ![](https://secure.gravatar.com/avatar/947be7e3fe72d711a506739fa280376b9985c11cc9005f1b6ae2eedece99d515? s=60&d=retro&r=g) ### 󠀁[Completes Block Editor](https://wordpress.org/support/topic/completes-block-editor/)󠁿 [Masud Rana](https://profiles.wordpress.org/yeelloo/) September 26, 2023 1 reply Can’t think of Block Editor without this. Tiny powerful thing. Only thing I hate in this plugin is the following line: $render_css = empty( $file_name ) || strpos( $file_name, ‘post-v2’ ) === false; This means if you deactivate Otter, your content might just break 🙁 [ Read all 25 reviews ](https://wordpress.org/support/plugin/blocks-css/reviews/) ## Contributors & Developers “Blocks CSS: CSS Editor for Gutenberg Blocks” is open source software. The following people have contributed to this plugin. Contributors * [ Hardeep Asrani ](https://profiles.wordpress.org/hardeepasrani/) * [ Themeisle ](https://profiles.wordpress.org/themeisle/) “Blocks CSS: CSS Editor for Gutenberg Blocks” has been translated into 8 locales. Thank you to [the translators](https://translate.wordpress.org/projects/wp-plugins/blocks-css/contributors) for their contributions. [Translate “Blocks CSS: CSS Editor for Gutenberg Blocks” into your language.](https://translate.wordpress.org/projects/wp-plugins/blocks-css) ### Interested in development? [Browse the code](https://plugins.trac.wordpress.org/browser/blocks-css/), check out the [SVN repository](https://plugins.svn.wordpress.org/blocks-css/), or subscribe to the [development log](https://plugins.trac.wordpress.org/log/blocks-css/) by [RSS](https://plugins.trac.wordpress.org/log/blocks-css/?limit=100&mode=stop_on_copy&format=rss). ## Changelog You can check the changelog [here.](https://github.com/Codeinwp/otter-blocks/blob/master/CHANGELOG.md) ## Meta * Version **3.1.8** * Last updated **4 days ago** * Active installations **5,000+** * WordPress version ** 6.2 or higher ** * Tested up to **6.9.4** * PHP version ** 5.4 or higher ** * Languages * [Chinese (Taiwan)](https://tw.wordpress.org/plugins/blocks-css/), [Dutch](https://nl.wordpress.org/plugins/blocks-css/), [Dutch (Belgium)](https://nl-be.wordpress.org/plugins/blocks-css/), [English (US)](https://wordpress.org/plugins/blocks-css/), [French (Canada)](https://fr-ca.wordpress.org/plugins/blocks-css/), [Hebrew](https://he.wordpress.org/plugins/blocks-css/), [Russian](https://ru.wordpress.org/plugins/blocks-css/), [Spanish (Spain)](https://es.wordpress.org/plugins/blocks-css/), and [Swedish](https://sv.wordpress.org/plugins/blocks-css/). * [Translate into your language](https://translate.wordpress.org/projects/wp-plugins/blocks-css) * Tags * [block](https://twd.wordpress.org/plugins/tags/block/)[css](https://twd.wordpress.org/plugins/tags/css/) [css editor](https://twd.wordpress.org/plugins/tags/css-editor/)[gutenberg](https://twd.wordpress.org/plugins/tags/gutenberg/) * [Advanced View](https://twd.wordpress.org/plugins/blocks-css/advanced/) ## Ratings 4.9 out of 5 stars. * [ 23 5-star reviews ](https://wordpress.org/support/plugin/blocks-css/reviews/?filter=5) * [ 1 4-star review ](https://wordpress.org/support/plugin/blocks-css/reviews/?filter=4) * [ 1 3-star review ](https://wordpress.org/support/plugin/blocks-css/reviews/?filter=3) * [ 0 2-star reviews ](https://wordpress.org/support/plugin/blocks-css/reviews/?filter=2) * [ 0 1-star reviews ](https://wordpress.org/support/plugin/blocks-css/reviews/?filter=1) [Add my review](https://wordpress.org/support/plugin/blocks-css/reviews/#new-post) [See all reviews](https://wordpress.org/support/plugin/blocks-css/reviews/) ## Contributors * [ Hardeep Asrani ](https://profiles.wordpress.org/hardeepasrani/) * [ Themeisle ](https://profiles.wordpress.org/themeisle/) ## Support Got something to say? Need help? [View support forum](https://wordpress.org/support/plugin/blocks-css/)