Markdown Compare Tool

Markdown compare two files side by side with real-time line diffing, synchronized scrolling, an unlimited file queue, live editing, and rendered preview — all 100% private in your browser.

L:
R:
LEFT: File 1
1
RIGHT: File 2
1
Comparing File 1 vs File 2
✓ 100% Private Client-Side

Markdown Compare: See Exactly What Changed, Line by Line

This free Markdown compare tool does more than split two panes — it runs a real line-by-line diff. Lines removed from the original are marked red (−); lines added in the revision are marked green (+), with a running count of every change.

Original (Left)
v1 · original− Legacy install steps− Old pricing note
Revised (Right)
v2 · revised+ One-line quick start+ 2025 pricing table

One Workspace for Every Markdown Comparison

The Markdown compare workspace keeps a file queue, two editors, and the live diff in a single view. Load your documents, choose any two to line up, and read every change without leaving the page — nothing is ever uploaded.

markdownviewer.org/markdown-compareFiles (3)L: v1R: v2SideUnifiedDiffEditPreviewSyncUpload++2−2SET LEFTSET RIGHTSET LEFTSET RIGHTSET LEFTSET RIGHTLEFT: v1RIGHT: v2−−++Comparing v1 vs v2 — file queue, diff, edit & preview✓ 100% Private Client-Side
The Markdown compare workspace — a collapsible file queue, two side-by-side panes with red and green line diffing, and a live +added / −removed tally.
Side-by-SideUnifiedDiffEditPreviewSIDE-BY-SIDEUNIFIED STREAM−++

Two Layouts, Three Ways to Read the Diff

Every Markdown compare layout adapts to the document in front of you. Read two files in parallel with synchronized panes, or collapse them into a single unified stream — then choose whether you want to inspect, edit, or preview the result.

  • Side-by-Side dual panes or a full-width Unified Stream
  • Diff Highlight, live Edit Raw, and rendered Preview HTML
  • Old and new line numbers shown on every changed line
  • A live +added / −removed tally that updates as you type

Everything the Markdown Compare Tool Does

More than a split view — the Markdown compare tool is a full comparison workspace for diffing, editing, and previewing your documents.

Visual Line-by-Line Diff

The Markdown compare engine runs a real line diff across both documents. Lines removed from the original glow red (−) and new lines glow green (+), with a live +added / −removed tally in the toolbar and footer.

Side-by-Side & Unified Layouts

Markdown compare supports two layouts: read files in parallel panes, or flip to a single Unified Stream that interleaves every change and keeps both old and new line numbers in view.

Diff, Edit & Preview Modes

Switch your Markdown compare view between the highlighted diff, a live raw-Markdown editor you can type into, and a rendered HTML preview with GitHub styling.

Multi-Document File Queue

Load as many files as you like into one Markdown compare session. The collapsible file sidebar keeps every document a click away, so you never juggle extra browser tabs.

Set Left, Set Right & Swap

Point any two documents at the Left and Right panes from the sidebar or toolbar dropdowns, then reverse the comparison instantly with the one-click swap button.

Drag, Drop & Batch Upload

Drop a whole folder of .md, .markdown, or .txt files onto the Markdown compare workspace, or upload several files at once into either pane.

Synchronized Scrolling

Lock both panes together so matching sections stay aligned while you scroll long documents — or move each side independently.

Copy & Download as .md

Copy either side to the clipboard or export your Markdown compare result as a clean .md file — one dedicated button per pane, no extra steps.

Fullscreen Focus Mode

Expand the whole Markdown compare workspace to fill the screen for a distraction-free, side-by-side review of dense documents and long histories.

How to Compare Markdown in 3 Steps

No account, nothing to install — open the Markdown compare tool, load two files, and the diff appears instantly.

1

Load your Markdown files

Drag and drop .md files onto the Markdown compare workspace, click Upload to add several at once, or press Add to start blank documents.

2

Select Left and Right documents

Use Set Left / Set Right on any file in the Markdown compare queue, choose Side-by-Side or Unified Stream, and turn on Sync Scroll to align panes.

3

Inspect diff, edit & export

Read the color-coded line diff, jump into Edit Raw to fix text live, flip to Preview HTML, then copy or download your result as .md.

Your Markdown Never Leaves Your Browser

Most online diff tools upload both files to a server before showing a result. This Markdown compare tool skips that entirely — the diff, the editor, and the preview all run locally in your browser tab, so private drafts stay private.

  • Both documents are diffed, rendered, and edited entirely inside your browser tab — nothing is ever uploaded to a server.
  • The Markdown compare tool runs 100% offline using client-side JavaScript once the page has loaded.
  • Your sensitive drafts, contract revisions, and internal documentation stay private on your local machine.

Who Compares Markdown Files?

Writers, developers, reviewers, and AI builders all use Markdown compare for their revision workflows.

Developer Release Notes & Specs

Use Markdown compare to diff changelogs, API documentation, or project README files line by line before shipping code to main.

Content Writers & Technical Editors

Spot edits with Markdown compare, proofread technical articles, and review contributor pull requests without missing small wording changes.

Document Version Control

Use Markdown compare to review changes to specs, config notes, or meeting minutes side by side, then sign off with confidence about what moved.

AI Output Comparison

Markdown compare two LLM answers or prompt variants to see exactly how their wording and structure differ line by line.

Need to Markdown Compare More Than Two Files?

The dedicated Markdown compare tool on this page diffs two documents at a time. If you need to open, preview, and batch-compare five, ten, or even more Markdown files in a single session, head to the Markdown Viewer homepage — it features a full multi-document workspace with tabs, a file sidebar, and a one-click Compare Documents action.

  • Open unlimited documents in a tabbed workspace
  • Select any subset and batch Markdown compare them instantly
  • Side-by-side multi-column rendered preview for every file
  • Export, rename, or ZIP all documents in bulk
Open Markdown Viewer
WelcomeUntitled 3Untitled 4Untitled 5Markdown C…+Sync scrollCompare 5×COMPARING 5 DOCUMENTSSelect a column · each keeps its own Edit / Preview modeDOCS5All×WelcomeUntitled 3Untitled 4Untitled 5Untitled 6Compare documentsExport ZIPRename documentsDelete documentsjavascriptYesYes✓ 100% Private

Markdown Compare — Frequently Asked Questions

Everything you need to know about comparing Markdown files here.

How does the Markdown compare line diff work?
The Markdown Compare tool compares the Left and Right documents line by line using a longest-common-subsequence diff algorithm. Lines removed from the original are highlighted red (−), lines added in the revision are highlighted green (+), and a running count is shown in the toolbar.
Can I Markdown compare more than two files at once?
Yes. Load as many files as you want into a single Markdown compare session — they all live in the collapsible file sidebar. Pick any two to compare at a time.
What is the difference between Side-by-Side and Unified Stream?
In Markdown compare, Side-by-Side shows the two documents in parallel panes with synchronized scrolling. Unified Stream merges everything into one column that interleaves removed and added lines.
Can I edit the Markdown while I compare it?
Yes. Switch either Markdown compare pane to Edit Raw and it becomes a live editor you can type into — changes update the diff in real time.
Does Markdown compare support drag-and-drop and batch upload?
Yes. Drop one or many .md files anywhere on the Markdown compare workspace and they load in bulk. You can also click Upload to add multiple files at once.
Can I preview rendered Markdown, not just the raw diff?
Yes. The Markdown compare Preview HTML mode renders each side with GitHub-style formatting so you can read the final output alongside the diff.
Is my text uploaded to a server?
No. The entire Markdown compare process — diffing, rendering, editing, and file handling — happens 100% locally inside your web browser tab.
Which file types and sizes does Markdown compare support?
You can load .md, .markdown, and .txt files of any size into the Markdown compare tool. The diff engine handles thousands of lines per document without slowdowns.
Can I copy or download the result after a Markdown compare?
Yes. Each pane has a dedicated Copy and Download button. After reviewing or editing the diff, export either document as a clean .md file — no extra steps required.
Does Markdown compare work on mobile devices?
Yes. The Markdown compare workspace is fully responsive. On smaller screens the layout adjusts automatically, and you can still upload, diff, edit, and export your files.
How do I swap the Left and Right documents in Markdown compare?
Click the swap button between the Left and Right dropdowns in the toolbar. The Markdown compare tool instantly reverses the comparison so the original becomes the revision and vice versa.
Can I Markdown compare more than two files at the same time?
The dedicated Markdown compare tool on this page diffs two documents at a time. For batch comparison of five or more files, visit the Markdown Viewer homepage — it offers a full multi-document workspace with a one-click Compare Documents action.

Compare Your Markdown Files Now

Scroll back up to the Markdown compare workspace, select or upload your files, and inspect line-by-line diffs in real-time — free, private, and with no sign-up.