Can I compare code files online without installing software?

Yes. Upload or paste any text-based code file (JavaScript, TypeScript, Python, HTML, CSS, SQL, Go, Ruby, Rust) into either panel. Lines mode with Split view works best for code. Everything runs in your browser with no installation needed.

Is my text uploaded to a server when I compare?

No. The difference checker is entirely client-side. All comparisons happen in your browser using JavaScript. Your text is never sent to a server, logged, or stored. It is safe to use with private code, confidential documents, and internal data.

Can I use this tool to compare CSV or spreadsheet data?

Yes. Paste or upload two CSV exports and use Lines mode to compare row by row. Each changed cell will appear on a changed line. For a cleaner view, enable Trim lines to remove accidental spacing around commas.

Can I compare large documents or log files?

Performance depends on your browser and device. For most documents up to several hundred kilobytes the tool runs smoothly. For very large files (multi-megabyte logs), consider comparing sections at a time or using a desktop diff tool. You can upload files directly rather than pasting to avoid clipboard size limits.

Difference Checker – Compare Text, Code & JSON Online

Q: What is the difference between split view and unified view?

Split view displays the original and changed text side by side in two columns, making it easy to compare matching lines. Unified view shows a single column with a '+' or '−' prefix and line numbers for each change, similar to a Git diff output.

Q: What is word-level diff and how does it work?

In Split view, when a line has changed, the tool runs a secondary word-by-word comparison on that specific pair of lines. Removed words are struck through in red on the left, and added words are highlighted in green on the right. This makes it easy to spot one changed word in a long line.

Q: What does the similarity score mean?

The similarity score shows the percentage of characters that are identical in both texts. A score of 100% means the texts are identical. A score of 0% means nothing matches. It gives you a quick sense of how much changed before you read the detailed diff.

Q: How do I compare two JSON files online?

Paste both JSON objects into the panels, enable Pretty JSON to normalize formatting, and optionally enable Sort keys to ignore key order differences. Only real value changes will be highlighted. This is especially useful when comparing API responses from different environments.

Q: Which file types can I upload and compare?

Any text-based format works: .txt, .md, .json, .js, .ts, .tsx, .html, .css, .sql, .yml, .yaml, .csv, .xml, .ini, .log, .py, .rb, .go, .rs, and more. Binary formats like PDF, DOCX, and images are not supported, but you can paste text extracted from them.

Q: What does 'Ignore whitespace' do?

When Ignore whitespace is enabled, sequences of spaces, tabs, and newlines are collapsed into a single space before comparison. Changes caused only by extra indentation or trailing spaces will not be flagged as differences.

Q: What is the difference between Lines, Words, and Characters mode?

Lines mode compares the texts one line at a time, best for code, documents, and logs. Words mode splits the text by spaces and compares individual words, ideal for reviewing prose edits in articles or emails. Characters mode compares every single character, which is useful when you need to spot a single changed letter, digit, or punctuation mark.

Original	Changed
1	The quick brown fox jumps over the lazy dog.	1	The quick brown fox leaps over the sleepy cat.
2	This line is unchanged.	2	This line is unchanged.
3	Hello world.	3	Hello there, world!

Difference Checker: Compare Two Texts, Code Files & JSON Online

This free online difference checker shows exactly what changed between two versions of any text, code file, or JSON document. Paste or upload your content, choose how precise you want the comparison, and see additions highlighted in green and removals in red. Everything runs instantly in your browser, with nothing sent to a server.

Most diff tools give you a flat list of changes. This one goes further. Split view places both versions side by side so your eye can move directly to what's different on each line. Word-level diff then runs a secondary comparison on each changed line, highlighting the specific words that changed rather than the entire line. A live similarity score shows you at a glance how much the two texts overlap.

How to compare two texts

Paste or upload the original version into the left panel and the revised version into the right panel. You can drag and drop a file directly onto either panel.
Choose a mode: Lines for code and documents, Words for prose, Characters for symbol-level changes.
Tune the options: Ignore whitespace, Ignore case, Trim lines, or Pretty JSON to remove formatting noise.
Review the diff: switch between Split and Unified views, jump between differences with the ↑ ↓ buttons.
Export: copy to clipboard, download as .txt, or download as a colored .html file.

Advanced features not found on other diff tools

SPLIT VIEW

True side-by-side comparison

Unlike most diff tools that only show a single-column unified output, Split view places original and changed text in two aligned columns, matching unchanged lines side by side so your eye only moves to what's different.

WORD-LEVEL DIFF

Highlights the exact changed word

When a line changes, a secondary word-by-word comparison runs on that line pair. Removed words are struck through in red; added words are underlined in green. No more scanning an entire line to find the one word that changed.

SIMILARITY SCORE

Instant similarity percentage

A live badge shows what percentage of the text is identical. Green means mostly unchanged, yellow means moderate edits, red means heavy rewrites. Useful when you need a quick read before diving into the full diff.

JUMP NAVIGATION

Jump to next / previous difference

Click the ↑ ↓ arrows in the toolbar to scroll directly to each difference in sequence. No more manual page-scrolling through unchanged lines to find the next change.

FILE EXPORT

Export as colored HTML or plain .txt

Download the diff as a self-contained .html file with green and red highlights that opens in any browser, perfect for attaching to pull requests, bug reports, or email. Or grab the classic unified .txt format.

JSON AWARE

Smart JSON normalization

Pretty JSON reformats both sides consistently, and Sort keys alphabetizes every object before comparing. This means a JSON diff only flags real value changes, not accidental differences in whitespace or key order.

What people use this diff checker for

Code review: compare two versions of a function, config file, or script before merging. Use Lines + Split view to see exactly what changed in each function.
Document version control: check what was added or removed between two drafts of a report, contract, or article without a version control system.
API response comparison: diff JSON responses from staging vs production with Pretty JSON and Sort keys to ignore formatting noise and focus on value differences.
Contract and legal review: compare two versions of an NDA, SLA, or terms of service document. Runs client-side, so no confidential content is shared.
CSV and data export verification: paste two exports and use Lines mode to spot rows that were added, removed, or modified between reporting periods.
Log file analysis: upload two log snapshots and see which lines appeared or disappeared, useful for debugging environment-specific issues.
Content proofreading: compare an original article against an edited draft in Words mode to review every word-level change an editor made.
Configuration file audits: diff two server config files (.yaml, .ini, .env) to confirm what changed between a working and broken environment.

Your privacy: text never leaves your browser

The entire diff algorithm runs in your browser using JavaScript. No text is sent to any server, no data is logged, and nothing is stored between sessions. You can safely compare private source code, confidential contracts, internal API payloads, and personal documents without any risk of data exposure.

Frequently asked questions

How do I compare two texts online for free?

Paste the original text in the left panel and the revised version in the right panel. Choose Lines, Words, or Characters mode and the differences appear instantly, color-coded in green for additions and red for removals. No account or software required.

What is the difference between split view and unified view?

Split view shows the original and changed text side by side in two columns with matching lines aligned, ideal for quickly spotting what moved or changed. Unified view uses a single column with + and minus prefixes and line numbers, similar to a Git diff, which works well for narrower screens or copy-paste into tickets.

What is word-level diff and how does it work?

In Split view, when a line has changed the tool runs a second word-by-word comparison on that specific pair of lines. Removed words are struck through on the left; added words are highlighted on the right. This makes it easy to spot one changed word in a long sentence without reading the whole line.

What does the similarity score mean?

The similarity score is the percentage of characters that match in both texts. 100% means the texts are identical. It gives you an instant read on how large the edit was before you read the detailed diff.

How do I compare two JSON files online?

Paste both JSON objects, enable Pretty JSON to normalize indentation, and optionally enable Sort keys to neutralize key-order differences. Only real value changes appear in the diff. Essential when comparing API responses across staging and production environments.

Which file types can I upload and compare?

Any text-based format: .txt, .md, .json, .js, .ts, .tsx, .html, .css, .sql, .yml, .yaml, .csv, .xml, .ini, .log, .py, .rb, .go, .rs, and more. Binary formats like PDF and DOCX are not supported, but you can paste extracted text.

Is my text sent to a server?

No. The entire comparison runs in your browser using JavaScript. Nothing is transmitted, logged, or stored. Safe to use with private code, confidential documents, and internal data.

What does Ignore whitespace do?

It collapses consecutive spaces, tabs, and newlines into a single space before comparing. Useful when comparing code that was auto-formatted or documents with inconsistent spacing, so you only see content changes and not formatting noise.

What is the difference between Lines, Words, and Characters mode?

Lines mode compares line by line, best for code, documents, and log files. Words mode splits by spaces, ideal for reviewing prose edits. Characters mode compares every single character, useful for spotting a changed digit, punctuation mark, or Unicode character.

How do I export the diff result?

Click Export in the toolbar. Download a .txt file in standard unified diff format, or a .html file: a self-contained colored page you can open in any browser or attach to a pull request or bug report.

How do I jump between differences without scrolling?

Use the ↑ ↓ arrow buttons in the results toolbar. Each click jumps to the previous or next changed segment and briefly highlights it so it's easy to find in a long diff.

Why do I see unexpected results in the diff?

Your active options shape what counts as a difference. Ignore whitespace hides spacing changes. Ignore case treats uppercase and lowercase as identical. Trim lines strips leading and trailing spaces from each line first. Toggle them to match the precision you need.

Can I compare CSV or spreadsheet data?

Yes. Paste or upload two CSV exports and use Lines mode to compare row by row. Enable Trim lines to remove accidental whitespace around commas for a cleaner result.

Can I compare large log files?

Performance depends on your browser and device. Documents up to a few hundred kilobytes run smoothly in most modern browsers. For very large files, compare in sections or use a desktop tool. Uploading a file is faster than pasting very long text.

Can I use this tool to check contract or legal document changes?

Yes. Paste two versions of a contract, NDA, or policy document into the panels and use Lines or Words mode. The diff highlights every added clause and removed sentence. Since everything runs in your browser, no text is shared with any server.

JSON Formatter

Format and validate JSON before comparing

Text Cleaner

Remove noise from text before running a diff

Word Counter

Count words, characters, and lines in any text

Find and Replace

Bulk-replace text in a document before comparing

Remove Duplicates

Deduplicate lines to simplify a comparison

Sort Lines

Sort lines alphabetically to normalize order

Case Converter

Normalize case before an ignore-case diff

URL Encoder / Decoder

Decode URL-encoded strings before diffing

Difference Checker

Original Text

Changed Text