Read Markdown
as real pages

What sets it apart

Most Markdown tools are editors with a preview on the side, or a web page squeezed into a window. Fast Markdown Viewer is built for reading, from its own engine up, and that is where its differences come from.

Installation

Fast Markdown Viewer is a single Windows application. Once installed it appears in your Start menu and in the Open with list of Markdown files.

The Window

The navigation on the left takes you to the pages of the app: Home, the Viewer, Export to PDF, Export to web page, Recent and Settings. You read in the Viewer.

The command bar is kept small. Every button shows its name when you hover over it, and the commands you need less often are grouped in two menus:

Opening Documents

Open one file, several, or a whole folder. However they arrive, the documents are read one after the other, like the chapters of a book.

📂 Files and folders

• Drop files or folders on the window. A folder brings its Markdown files, and those of its subfolders unless you turn that off in Settings.
• File → Open files (Ctrl+O) or File → Open folder (Ctrl+Shift+O).
• Double-click a Markdown file in File Explorer, or choose Open with → Fast Markdown Viewer.
• Pick a file or a folder again from Recent.

When a folder holds an index of the others, a README.md that links to the chapters for instance, it is read first and the rest follow in a natural order, Chapter 2 before Chapter 10. A text file of another kind, a .txt or a log, is opened as plain text, and the app asks when it cannot tell whether a file is Markdown.

🔗 Following links

Click a link to another Markdown file and that document joins the ones open, at the heading the link names. Tick Follow links in the open dialogs and the app opens, along with your file, every Markdown file it links to in the same folder, and the files those link to, so a set of notes or a small manual opens whole in one go. Hover over a link to see a picture of where it leads before you click.

A link to a web page opens your browser, a link to another kind of file opens it in its own application. Back and Forward bring you back to where you were, and so do Alt+←, Alt+→ and the side buttons of your mouse.

🔄 Documents that change

Writing in another program and reading here? Save there and the page updates here, at the place you were reading. Refreshing is automatic, it can be turned off in Settings, and F5 rereads every document whenever you like.

🖼️ Pictures

Pictures next to your documents are shown, PNG, JPEG, GIF, BMP, TIFF, WebP and the other formats Windows reads, and SVG drawings stay sharp at every zoom. Click a picture to see it on its own over the page, then zoom it with Ctrl and the mouse wheel. Pictures a document takes from the internet are only shown when you allow it, see Settings.

Views & Zoom

Three ways to arrange the pages, all with the same zoom and the same place in the document.

🔍 Zoom

Hold Ctrl and turn the mouse wheel, the spot under the pointer stays where it is. The zoom out and zoom in buttons, Ctrl+- and Ctrl++ do the same from the middle of the view. Click the percentage for 50 % to 400 % and Fit, which is also Ctrl+0, while Ctrl+1 shows the pages at their real size. Text, diagrams, formulas and SVG drawings are drawn again at every zoom, never stretched.

✋ Pan

Hold the right mouse button down and drag to move the pages under the window, in any view. It stops where the scroll bars stop, so you never lose the pages. A simple right click still opens the context menu.

🖥️ Full screen

Press F11, or choose View → Full screen, and the pages take the whole screen, nothing else around them. A small bar in the top right corner keeps the three views, Fit and the way back. Esc or F11 brings the window back.

Moving Around

📑 Contents

View → Contents (Ctrl+Shift+T) shows the headings of every open document beside the pages. Click one to go there, and the heading you are reading is highlighted as you scroll. Type in the box above the list to filter it.

📚 The list of documents

With several documents open, View → File names or File paths lists them on the left. Click a document to jump to its first page.

⌨️ With the keyboard

Page Down and Page Up go to the next and the previous page, Home and End to the first and the last, the arrows scroll a little. In the gallery the arrows move from page to page. Tab goes from link to link in reading order, across pages, Enter follows the link. Or type a page number in the box and press Enter.

Find, Select & Copy

🔎 Find in pages

Press Ctrl+F and type. Every page of every open document is searched, each match is highlighted, small ticks along the right edge show where the others are, and the count says how many there are. Enter or F3 goes to the next match, Shift+F3 to the previous one.

🖱️ Selecting

Drag over the text to select it, across pages if you like. Double-click selects a word, a third click the paragraph, Shift and a click stretch the selection, and Ctrl+A selects everything.

📋 Copying

Ctrl+C or the context menu copies the selection both as text and as formatted text, so it pastes with its bold, its links and its lists into Word or an email. Formulas go along as MathML, so they paste into Word as real, editable equations, see Math. Right-click a table and choose Copy table to paste it into Excel with every cell in its place.

View Source

Sometimes you want to see how a document was written. View → Source, or Ctrl+U, shows each file exactly as it is, every line as typed, in colour.

The source is shown on the same pages as the document, so everything works the same way: zoom, the three views, find, selecting part of it or all of it and copying it. Press Ctrl+U again to go back to the pages.

Page Styles

A page style is more than a colour scheme: it sets the fonts, their size, the space between the lines and every colour of the page, the code, the selection and the diagrams included.

Pick a style from the Page style button of the Viewer, from either export page, or in Settings. It is one choice for the whole app: the pages you read, the PDF, the pictures of pages and the web page you export, and the thumbnails and previews in File Explorer all follow it. The app's own light or dark theme is a separate setting, so you can read dark pages in a light window, or the other way round.

What It Reads

Fast Markdown Viewer reads CommonMark, the standard behind most Markdown, and GitHub's flavour of it, then the extras that documents use every day.

Diagrams

Write a diagram as text in a mermaid code block and it is drawn on the page. The app draws them itself, with no internet and no script, and they stay sharp at every zoom and in the PDF.

All thirty-two kinds of Mermaid diagrams are drawn, the newest ones included. The first word of the diagram says which it is:

A diagram can also be saved alone as a .mmd or .mermaid file, and opens like a document, with its thumbnail and its preview in File Explorer.

🔀 A flowchart

```mermaid
flowchart LR
    A([Idea]) --> B{Worth writing?}
    B -- Yes --> C[Draft in Markdown]
    B -- No --> D[Note it for later]
    C --> E[Read it as pages]
    E --> F([Export to PDF])
```

✏️ The same, hand drawn

Add look: handDrawn to a diagram's settings and it looks sketched on paper, wobbly double strokes and handwritten labels. The sketch is the same every time you open the file.

```mermaid
---
config:
  look: handDrawn
---
flowchart LR
    A([Idea]) --> B{Worth writing?}
    ...
```

↔️ A sequence diagram

```mermaid
sequenceDiagram
    actor Reader
    participant Viewer
    participant Explorer
    Reader->>Explorer: Selects notes.md
    Explorer->>Viewer: Asks for a preview
    Viewer-->>Explorer: The first page
    Reader->>Viewer: Double click
    Viewer-->>Reader: Every page, ready to read
```

📅 A Gantt chart

```mermaid
gantt
    title Writing the guide
    dateFormat YYYY-MM-DD
    section Draft
    Outline        :done, a1, 2026-03-02, 4d
    Chapters       :active, a2, after a1, 10d
    section Review
    Read as pages  :b1, after a2, 3d
    Export the PDF :milestone, after b1, 0d
```

🥧 A pie chart

```mermaid
pie title Where the time went
    "Writing" : 46
    "Reading back" : 24
    "Diagrams" : 18
    "Exporting" : 12
```

🧠 A mind map

```mermaid
mindmap
  root((Markdown))
    Reading
      Pages
      Gallery
      Find
    Writing
      Tables
      Math
      Diagrams
    Sharing
      PDF
      Web page
```

🕒 A timeline

```mermaid
timeline
    title A document's life
    Monday : First draft
    Wednesday : Diagrams added : Math checked
    Friday : Read as pages
    Saturday : Sent as a PDF
```

🧮 A quadrant chart

```mermaid
quadrantChart
    title Which document to read first
    x-axis Short --> Long
    y-axis Less urgent --> More urgent
    quadrant-1 Plan time for it
    quadrant-2 Read it now
    quadrant-3 Skim it
    quadrant-4 Keep for later
    Meeting notes: [0.2, 0.8]
    Design guide: [0.8, 0.7]
    Release notes: [0.3, 0.3]
    Handbook: [0.85, 0.2]
```

🌊 A Sankey diagram

Flows between stages, each band as wide as its amount, with the totals beside each node.

```mermaid
---
config:
  sankey:
    showValues: true
---
sankey-beta
Solar,Electricity,62
Wind,Electricity,88
Hydro,Electricity,41
Nuclear,Electricity,104
Gas,Electricity,57
Gas,Heating,73
Oil,Transport,121
Oil,Industry,28
Biomass,Heating,19
Biomass,Electricity,12
Electricity,Homes,121
Electricity,Industry,96
Electricity,Transport,38
Electricity,Losses,109
Heating,Homes,64
Heating,Offices,28
Transport,Road,131
Transport,Rail,28
Industry,Steel,52
Industry,Chemicals,72
```

∑ Math inside diagrams

A label can hold a formula: write it between $$ in the label, alone or after some words, and it is drawn with the same math engine as the rest of the page.

```mermaid
flowchart LR
    A["$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$"] --> B["$$\Delta = b^2 - 4ac$$"]
    B --> C{"$$\Delta > 0$$"}
    C -- yes --> D["Two roots $$x_1 \ne x_2$$"]
    C -- no --> E["$$x = -\frac{b}{2a}$$"]
```

🎨 Themes and settings

Without a theme of its own, a diagram takes the colours of your page style, so it always matches the page. Name one of Mermaid's ten themes in its settings, default, neutral, forest, dark, base or the newer ones, and it keeps that look whatever the page style. A diagram's own settings, its colours, its direction, its spacing, are read too.

Math

Formulas are written in TeX, the syntax KaTeX and MathJax read and GitHub uses, and drawn by the app itself with the Cambria Math font, no web page and no script involved.

Fractions, roots, sums, integrals, matrices, cases, Greek letters, accents and colours are drawn the way a textbook prints them, and formulas stay sharp at every zoom and in the PDF. Formulas also work inside diagrams.

Code

Code blocks are coloured when they name their language: keywords, text, numbers and comments each have their colour, taken from your page style.

The languages coloured are C, C++, C#, Java, Kotlin, JavaScript, TypeScript, Go, Rust, Swift, Python, Ruby, PHP, Lua, shell scripts, PowerShell, batch files, SQL, JSON, YAML, TOML and INI files, CSS, HTML and XML, Markdown itself and diffs. A long line wraps rather than being cut, and a drawing made of characters, a table of boxes or a tree, is made smaller to fit the page rather than broken.

Export to PDF

Fast Markdown Viewer writes its PDFs itself, no printer and no driver involved, and gives you exactly the pages you were reading.

📕 What the PDF holds

⚙️ Options

Click Export…, choose where to save, and the PDF is written in the background. A bar then offers to open it.

<!--
output-file: Field guide version 1.0
-->

Export to Web Page

Save the open documents as one web page that opens in any browser, on any computer or phone.

Tick the pages as for the PDF: every document with a ticked page is saved whole, since a web page has no pages, in the order of its first ticked page. The pictures, the diagrams and the formulas are inside the file, so it is a single file you can send or put online. The fonts and colours of your page style come along, and code is coloured.

Pages as Pictures

Right-click a page and choose Save page as image to save it as PNG, JPEG, TIFF, BMP, GIF or any other format your Windows can write, HEIC included when its extension is installed, in the page style you read it in, at a size sharp enough for a slide or a printout.

AI Assistants

If you use an AI assistant on your PC, such as Claude, ChatGPT, GitHub Copilot or LM Studio, it can work with Fast Markdown Viewer for you. Ask it in your own words about the document you are reading, to open a file, or to make a PDF, and it does it in the app.

🔌 Connect your assistant in two steps

• Allow it. In Settings, under AI assistants, turn on Let AI assistants use Fast Markdown Viewer. It is off until you turn it on, and you can turn it off again at any time.
• Connect your app. Just below, open Connect an AI app and click the button next to the app you use. Most apps then open and ask you to confirm, see the table.

🔒 What your assistant can see

Only what you ask about, and only while Let AI assistants use Fast Markdown Viewer is on. When your assistant asks, it gets the text of the document on screen, the page and the section you are on, and the names of the other open documents. It cannot see your other files through Fast Markdown Viewer, and it cannot change your documents: the app only reads them, and writes the PDFs and web pages you ask for.

📌 Good to know

What to Ask

There are no commands to learn. Talk to your assistant as you would to a person sitting next to you. These conversations show the kind of things that work well, the answers are examples.

📖 About what you are reading

🔎 Finding your way

📂 Opening documents

📕 Making a PDF or a web page

✨ Several steps at once

An assistant can chain the steps itself, and do its own part in between.

File Explorer

Once installed, File Explorer shows your Markdown files the way the app does, without opening anything.

Thumbnail

Preview pane

👁️ Using the preview pane

The preview is drawn in the background, so Explorer never waits on a long document. A very large file, tens or hundreds of megabytes, shows its first page at once: the others are measured behind it, and the bar says 1 / 3553+ until the last one is known. A style changed in the app's settings shows in a preview that is already open.

🎨 The style of thumbnails and previews

Thumbnails and previews are drawn in the app's page style, unless you pick another one for Explorer in Settings → Windows Explorer → Page style in Explorer: light thumbnails in a dark app, for instance. Windows keeps the thumbnails it has already drawn, so use Reset Explorer thumbnails on the same page to see the new style on them.

Better Shell Integration (administrator required)

Markdown files are often claimed by a code editor, and Windows then shows that program's plain icons and no preview. Better Shell Integration registers Fast Markdown Viewer's thumbnails, preview and details with Windows itself, so they show whatever app opens your Markdown files.

🛠️ Install, update, uninstall

Everything is in Settings → Shell Integration. The card shows whether it is installed and offers Install, Update when a newer app brings a newer version, Reinstall if thumbnails or previews stop appearing, and Uninstall. Each asks for administrator approval, because Windows keeps these registrations in a place only an administrator can change. It is also listed in Settings → Apps → Installed apps and can be removed there.

Accessibility

The pages are drawn by the app itself, and the app makes sure they are just as readable without seeing them or without a mouse.

Settings

🎨 Appearance & behaviour

🗂️ Windows Explorer

🤖 AI assistants

♻️ And more

Reset settings brings every setting back to its default, and the licence card shows how long the trial has left.

Keyboard Shortcuts

Files

View

Zoom

Moving around

Find & copy

Tips & Tricks

✍️ Write in your editor, read here

Keep your editor on one side and Fast Markdown Viewer on the other, pinned on top. Every time you save, the page updates where you were, so you see your document as pages while you write it.

📖 Long reading

Pick the Book style, go full screen with F11, and turn the pages with Page Down. The contents panel, Ctrl+Shift+T, takes you to any chapter.

🌙 Dark pages in the evening

The application theme and the page style are separate: a light window with Nord or Dark dimmed pages, or a dark window with Sepia pages, whatever suits your eyes.

📊 Check a diagram while writing it

Save a diagram alone as a .mmd file and open it: it is redrawn every time you save, and its thumbnail in Explorer shows what it looks like.

📨 Send a web page, not a zip

The exported web page carries its pictures, diagrams and formulas inside, one file that opens on any device, even a phone.

Troubleshooting

🖼️ A picture from the web shows only its description

Pictures from the internet are not downloaded unless you allow it, so opening a document never tells a website you read it. Turn on Show pictures from the web in Settings.

🔒 "File system error (-2143322102)" when opening a file

Your free trial has ended. Windows refuses to start an app whose Store licence is no longer valid, and shows the Store's licensing error without an explanation. Nothing is wrong with the file. Get Fast Markdown Viewer from the Microsoft Store and your files open again.

🗂️ Thumbnails only show in the icon views

Windows draws thumbnails in Explorer's icon views only. In Details or List view a folder shows the plain file icons, whatever the file. Choose Medium icons, Large icons or Extra large icons from Explorer's View menu, or hold Ctrl and turn the mouse wheel.

🥇 Another app shows its icons and no preview

Windows lets only the default app of a file type provide its thumbnails and preview, and Markdown files often belong to a code editor. Install Better Shell Integration, which keeps your default app and still gives you Fast Markdown Viewer's thumbnails and preview, or make Fast Markdown Viewer the default in Windows Settings → Apps → Default apps.

👁️ The preview pane stays empty

The preview pane belongs to Explorer and is closed until you open it, in each Explorer window: press Alt+P. On Windows 11 the Details pane and the Preview pane cannot be open at the same time. In Explorer's View → Show → Options, on the View tab, Show preview handlers in preview pane must be ticked.

🚫 No preview for files downloaded from the internet

Recent Windows 11 updates block the preview pane for files that carry the "Mark of the Web", downloaded files, for every file type. Right-click the file, choose Properties, tick Unblock at the bottom of the General tab and click OK. Newer updates show a Preview anyway button instead.

🖱️ The preview stops responding after a double-click (Windows 11)

On recent Windows 11 updates, double-clicking the file you are previewing can leave the preview pane unable to react, for every file type. Close that Explorer window and open a new one, or open the file from inside the app.

🤖 My AI assistant says it is not allowed, or that the app is not running

Turn on Let AI assistants use Fast Markdown Viewer in Settings. To read along or to export, Fast Markdown Viewer must also be open with a document in it. The message your assistant passes on says which of the two it is.

🔄 ChatGPT, Codex or Claude does not show Fast Markdown Viewer

These apps look for new tools when they start. Close the app completely, from its icon near the clock if it has one, and start it again. In Claude, check that Fast Markdown Viewer is listed and switched on in Settings → Extensions.

🔍 "Not found on this PC" when connecting

The AI app you picked is not installed, or Windows does not know how to open it. Install it, start it once, and click Connect again. For an app that is not in the list, use Another AI app → Copy.

⚠️ Claude warns that the extension is not verified

Claude shows this for every extension installed from a file rather than from its own directory. The file comes from Fast Markdown Viewer's Settings, on your own PC, and only starts Fast Markdown Viewer.