Marklane is built for fast publishing from Markdown. It helps editors turn local Markdown drafts into WordPress posts without copying content into the post editor by hand.

Write locally in Markdown, add YAML frontmatter for post settings, then import the file from Tools > Marklane. Marklane can create a new post or update an existing one by slug, apply categories, tags, dates, featured images, post status, and Polylang language links in one import. When frontmatter is omitted, it can derive a draft title and slug from the first H1 and filename.
If you enable Ignore invalid frontmatter, the plugin ignores only the invalid frontmatter keys and keeps the valid ones. If the YAML block itself is broken, it falls back to the filename and first H1 while keeping the selected post status and date options.
If you enable Mermaid rendering, Marklane can also turn ```mermaid code blocks into front-end diagrams while keeping the stored post content as ordinary Markdown code blocks.

Plugin page: https://happas.jp/marklane/

Features:

Fast Markdown publishing: import prepared Markdown files from the WordPress admin
YAML-controlled post settings: set title, slug, status, date, categories, tags, featured image, and language links
Safe re-imports: update existing posts by slug instead of creating duplicates
Dry Run preview: review the planned create/update action, category and tag assignment, image resolution, warnings, and errors before saving
Media Library image resolution: resolve relative Markdown image paths and featuredImage against existing attachments
Polylang support: connect translated posts from lang and translations frontmatter
Optional Mermaid rendering: render ```mermaid code blocks as diagrams on pages that contain them when enabled
Optional Extended Markdown: render common callout syntax such as GitHub alerts and Zenn messages when enabled
Optional Math rendering: render $$...$$ display formulas on pages that contain them when enabled
Light front-end loading: Mermaid and math assets load only on pages that contain matching content
CommonMark + GFM conversion: parse Markdown with league/commonmark

For the most predictable image resolution behavior, it is recommended to disable WordPress’s year/month based upload folders and to use fully unique filenames for Markdown files and image assets.

This plugin is best suited to workflows where:

articles are written locally in Markdown
WordPress is used as the publishing destination
editors want to keep the import source file manageable inside WordPress
repeated imports and post updates are part of the workflow

Frontmatter quick reference:

Marklane reads YAML frontmatter at the top of the Markdown file. Common keys include:

title
slug
postType
excerpt
status
date
category
tags
featuredImage
lang
translations

title falls back to the first H1 and then the filename. slug falls back to the filename. postType defaults to post, and status defaults to draft.

For more frontmatter examples:
https://happas.jp/en/marklane/#yaml-frontmatter-example

Known limitations:

Does not create custom post types or taxonomy definitions
Does not import ZIP archives
Does not import through REST API or WP-CLI
Does not download external image URLs automatically

Marklane – Fast Publishing from Markdown.