Inline Text Diff — Free Online Inline Text Diff

How do I compare two texts and see the differences online?

Paste your original text on one side and the changed text on the other in AnyTool Inline Text Diff. It highlights every difference live — additions in green, deletions struck through in red — at character, word or line level, in either a unified inline view or a side-by-side split. Everything is computed in your browser, so neither text is uploaded.

Character, word and line diff granularities, switchable instantly
Unified inline view and aligned side-by-side split view
Ignore case, ignore leading/trailing or all whitespace, trim lines
Live stats: additions, deletions, unchanged and a similarity percentage
Copy the diff or export a standard unified .diff / .patch — 100% client-side

What is

Text Diff

A text diff (or diff checker) is a tool that compares two pieces of text and shows what was added, removed or unchanged between them. It can compare at the character, word or line level and present the result inline or side by side, helping writers, editors and developers review edits and merge changes.

Text Tools

Related terms

Diff CheckerUnified DiffSide-by-Side ComparePatch File

Frequently Asked Questions

Both texts are diffed locally in your browser using JavaScript; large inputs are processed in a Web Worker to keep the page responsive. Nothing is sent to a server, there is no tracking, and the page works offline after first load — so you can safely compare confidential drafts, contracts or source code.

No upload happens. The comparison runs entirely in your browser, so neither text leaves your device and it works offline.

Character diff is the most granular — it pinpoints the exact letters that changed, which is useful for spotting typos. Word diff highlights whole changed words and reads best for prose and proofreading. Line diff treats each line as a unit and is ideal for code and structured text, where you care that a line changed rather than which characters within it.

Character diff marks individual characters that changed, word diff marks whole changed words, and line diff marks whole lines as added or removed.

Alongside copying the inline diff, the tool builds a standard unified diff with @@ hunk headers and surrounding context lines. You can copy it to the clipboard or download it as a changes.patch file and apply it later with git apply or the Unix patch command.

Yes. You can copy or download a standard unified diff, the .patch format that git apply and the patch command understand.

The ignore-options change only what counts as equal — your text is never modified. You can treat upper and lower case as the same, trim the edges of each line, or ignore whitespace entirely, so reformatting and re-indentation do not appear as real changes. Exports still use your original characters.

Toggle ignore case, trim leading/trailing whitespace, trim lines, or ignore all whitespace so cosmetic changes do not show as differences.

Detailed Explanation

Methodology

How the Inline Text Diff Works

AnyTool Inline Text Diff compares two texts entirely in the browser using the Myers diff algorithm from the jsdiff library. It tokenises each side into characters, words or lines depending on the chosen granularity, then computes the shortest sequence of additions and deletions that turns the original into the changed text. Ignore-options are applied through a comparator that normalises each token before comparison while always emitting the original text, so nothing the user typed is altered.

Three granularities: character, word and line-level diff
Token-based comparison so ignore-options never mutate the text
Ignore case, trim line edges, or ignore all whitespace
Large inputs are diffed in a Web Worker to keep the UI responsive
All computation is client-side JavaScript — no server round-trip

How It Works

Unified and Side-by-Side Views

The result can be read two ways. The unified inline view renders both texts as a single flow with additions shown in green and deletions struck through in red. The side-by-side split view aligns the original and changed text in two line-numbered columns, pairing changed lines into modify rows that carry a within-line word highlight so the exact edit is visible. Live statistics report additions, deletions, unchanged characters and a similarity percentage.

Unified inline view with green additions and red strikethrough deletions
Side-by-side split with aligned line numbers and modify rows
Within-line sub-highlighting on modified lines in split view
Similarity score derived from the common share of both texts
A standard unified diff / .patch can be copied or downloaded

Privacy & Security

Privacy and Offline Use

Because the entire comparison runs in the browser, neither text reaches a server, there is no account or tracking, and the page works offline after first load. This makes it safe to paste proprietary source code, API keys, contracts or unreleased drafts. The exported unified diff is a real .patch file that can be applied with git apply or the Unix patch command.

Text diffing: in-browser (AnyTool) vs typical online diff checkers
Capability	AnyTool	Typical online diff tools
Text handling	Processed in your browser	Often posted to a server
Privacy	Neither text leaves device	May log or store submitted text
Granularity	Character, word and line	Often word or line only
Views	Unified and side-by-side	Sometimes one view only
Ignore options	Case, trim and all whitespace	Often limited
Patch export	Unified .diff / .patch	Rarely offered
Works offline	Yes (PWA)	No

Server-based diff checkers can retain pasted text in logs; AnyTool computes the comparison locally and uploads nothing.