免費文字比較器教學：對比兩段文字差異、增刪改動即時顯示
1. 導言
無論你係要校對文章修改前後嘅分別、比對程式碼版本差異、檢查文件修訂內容，定係想快速了解兩段文字之間有咩改動，文字比較工具都係非常實用嘅幫手。但市面上好多比較工具一係要下載軟件，一係要將文字上傳到伺服器，私隱風險高。我哋嘅免費線上文字比較器專為解決呢啲問題而設：貼上兩段文字即時對比，新增、刪除、相同內容分別用顏色標示，而且 100% 純前端運算，文字唔會離開你嘅瀏覽器。
2. 背景與概念解釋
文字比較（Text Diff）係指對比兩段文字之間嘅差異，識別出新增、刪除同埋相同嘅部分。呢個技術最早源於 Unix 嘅 diff 指令，用於比對檔案內容嘅變化，後來廣泛應用於版本控制系統（如 Git）和文字編輯工具。
我哋嘅工具採用 Google 開發嘅 diff-match-patch 算法，能夠高效地計算兩段文字之間嘅最長共同子序列（LCS），並將差異標記為新增（綠色）、刪除（紅色）和相同（灰色）。所有運算喺你嘅瀏覽器內完成，文字由頭到尾都唔會離開你嘅裝置。
3. 實際應用場景
- 文章校對與編輯：比對修改前後嘅文章版本，快速檢查改動位置。
- 程式碼版本比對：比較兩個程式碼檔案嘅差異，方便 Code Review。
- 文件修訂追蹤：追蹤合約、報告等文件嘅修改歷程，確保內容準確。
4. 使用步驟
- 輸入兩段文字：喺「原始文字」貼上舊版本，喺「修改後文字」貼上新版本。
- 比較差異：點擊「比較差異」按鈕，或按 Ctrl+Enter（Mac 用 Cmd+Enter）。
- 查看結果：系統會顯示新增（綠色）、刪除（紅色）和相同（灰色）嘅文字對比。
- 複製結果：點擊「複製結果」即可將差異內容複製到剪貼簿。
5. 與其他方法比較
| 比較項目 |
本站前端工具 |
Git diff |
其他線上工具 |
| 使用成本 |
完全免費 |
免費（需安裝 Git） |
免費但有廣告或限制 |
| 數據私隱 |
100% 本地處理 |
本地處理 |
低（需上傳伺服器） |
| 視覺化展示 |
✅ 顏色標示新增/刪除 |
✅ 文字格式 |
✅ 通常有 |
| 相似度計算 |
✅ 即時顯示 |
❌ 不顯示 |
❌ 通常不顯示 |
| 使用門檻 |
極低 |
高（需學習 Git） |
中等 |
6. 個人經驗與觀點
「之前做網站內容更新嘅時候，成日要 check 新舊版本之間改咗啲咩。以前要逐段對比，好花時間又容易睇漏。後來用咗呢個文字比較器，貼上兩段文字就即刻睇到邊度新增咗、邊度刪除咗，仲有相似度顯示。對於成日要處理文字內容嘅人嚟講，呢個工具真係好實用。」
7. 總結與試用呼籲 (CTA)
Free Text Diff Tool Guide: Compare Two Texts with Add/Delete Highlight
1. Introduction
Whether you need to proofread article revisions, compare code versions, check document changes, or quickly see what's different between two texts, a text diff tool is an essential helper. Many diff tools require software installation or upload your text to servers—creating privacy risks. Our free online text diff tool solves these problems: paste two texts, compare instantly with color-coded adds and deletes—all with 100% client-side processing.
2. Background & Technical Concept
Text diff compares two texts to identify additions, deletions, and unchanged content. This technology originated from the Unix diff command for comparing file changes and is now widely used in version control systems like Git.
Our tool uses Google's diff-match-patch algorithm to efficiently compute the longest common subsequence (LCS) and highlight differences—additions in green, deletions in red, and unchanged content in gray. All processing happens locally in your browser, and your text never leaves your device.
3. Real-World Application Scenarios
- Article Proofreading & Editing: Compare article revisions to quickly identify changes.
- Code Version Comparison: Compare two code files for easier Code Review.
- Document Revision Tracking: Track contract and report revisions to ensure accuracy.
4. Step-by-Step Usage Guide
- Enter Two Texts: Paste the original version in "Original Text" and the revised version in "Changed Text."
- Compare: Click "Compare" or press Ctrl+Enter (Mac: Cmd+Enter).
- View Results: Highlights show additions (green), deletions (red), and unchanged (gray) content.
- Copy Result: Click "Copy Result" to copy the diff output.
5. Comparison with Alternative Solutions
| Feature |
Client-Side Tool (Us) |
Git diff |
Other Online Tools |
| Cost |
100% Free |
Free (Git required) |
Freemium / Ads |
| Privacy |
100% Local Processing |
Local Processing |
Low (Server Upload) |
| Visual Display |
✅ Color-Coded Add/Delete |
✅ Text Format |
✅ Usually |
| Similarity Score |
✅ Instant Display |
❌ Not Displayed |
❌ Usually Not |
| Ease of Use |
Very Low |
High (Git Knowledge) |
Medium |
6. Personal Insights & Expert Advice
"When I was updating website content, I often needed to check changes between old and new versions. I used to compare line by line—time-consuming and error-prone. Now I use this text diff tool—paste both versions and instantly see additions, deletions, and similarity score. For anyone who works with text regularly, this tool is a must-have."
7. Conclusion & CTA