Code Block Extractor

Extract every fenced code block from a Markdown document

Pull JavaScript, Python, Bash, JSON, Dockerfile, SQL, Mermaid, and 25+ other fenced languages out of any Markdown file. Filter by language, copy individual blocks, or download each as a real source file with the right extension.

Diagram inventory Reorder sections Open the editor

4 fenced block(s) · 4 language(s)

Markdown source

Block 1jsL31 line(s)

function add(a, b) { return a + b; }

Block 2pythonL92 line(s)

def add(a, b):
    return a + b

Block 3bashL141 line(s)

npm install my-package

Block 4jsonL181 line(s)

{ "ok": true }

How to use the code extractor

Paste Markdown or click Open .md to load a file.
The tool lists every fenced code block with its language, starting line, and line count.
Use the language pills to filter — show only bash, only python, etc.
For each block: Copy the body to clipboard, or Download with a sensible filename.
Use Copy all (as Markdown) to grab the visible blocks back as a fenced Markdown stream.

When this saves real time

Tutorial → runnable repo. A long step-by-step doc with ten bash + JS + JSON blocks becomes a real project in minutes.
Docs → tests. Pull snippets out of ```js fences and seed unit tests so prose and examples stay in sync.
README extraction. Quickly grab every Dockerfile / CI config example for review.
Cross-doc reuse. Cherry-pick the relevant snippet from a long migration guide for a different page.

Supported languages and extensions

The mapping covers the languages people actually paste into Markdown: JavaScript, TypeScript, Python, Go, Rust, Ruby, Java, Kotlin, Swift, Bash/Shell, PowerShell, C, C++, C#, PHP, JSON, YAML, TOML, CSS, SCSS, HTML, SQL, Dockerfile, GraphQL, Mermaid, TeX, diff, and patch.

Unknown languages fall back to .txt — rename after download.

Companion tools

Diagram Inventory & Mermaid Validator — focused inventory for Mermaid and math fences.
Markdown Outline Reorder — restructure the document around the extracted snippets.
Markdown Editor — paste a snippet back to see it rendered.

Privacy & data

Extraction is a small client-side parser. We don't upload, log, or store the Markdown you paste.

Frequently asked questions

Why extract code from Markdown?

Common reasons: turning a tutorial into a runnable sample folder, harvesting snippets from a doc for unit tests, copying just the bash commands from a long installation guide, or migrating a single doc into multiple per-language code files.

How are languages detected?

From the fence's language tag — the text after the triple backticks (`\`\`\`js`, `\`\`\`python`, etc.). Blocks without a language tag are labeled `plaintext`. The filter pills show counts per language so you can quickly isolate one type.

Are filenames safe to use?

Each block gets a suggested filename based on the language (e.g., `snippet-3.py`, `snippet-7.go`, `Dockerfile`). The default name combines the block index and the extension — adjust as needed before saving.

Does it preserve indentation and whitespace?

Yes. The extractor copies the exact body between the fences. Trailing whitespace and tab indentation are preserved byte-for-byte.

Can I export everything at once?

Click 'Copy all (as Markdown)' to grab every visible block re-wrapped in their fences — handy for moving snippets between docs. For a full filesystem export, download each block individually; a multi-file ZIP would require uploading the content, which we deliberately avoid.

Is the document uploaded?

No. Extraction is a string-parse operation that runs entirely in your browser.