SheetDiff™ is a schema-agnostic Google Sheets™ add-on that compares spreadsheet data and generates detailed quality assurance reports — all inside Google Sheets™.

Whether you're comparing transcript versions, reviewing translations, reconciling financial data, or auditing any tabular data — SheetDiff™ finds every difference, color-codes it, and gives you a professional report in seconds.

=== THREE POWERFUL COMPARISON MODES ===

🔍 STRUCTURAL DIFF
Compare an original snapshot against an edited version. Every row is categorized:
• UNCHANGED — identical rows
• MODIFIED — text or data changes (with inline green/red highlighting)
• SPLIT — one row became multiple rows
• MERGED — multiple rows combined into one
• ADDED — new rows in the edited version
• DELETED — rows removed from the original
• Simple Mode — streamlined add/delete/modify view with optional inline diffs
• Positional Mode — strict row-by-row comparison (row N vs row N), no time-based matching
• Unified Output — merge multi-sheet diffs into a single output grid
• Batch Comparison — compare against multiple sheets in one run

📊 CELL-BY-CELL COMPARISON
Compare a baseline sheet against one or more sheets, cell by cell:
• Three compare modes: Exact, Normalized (smart), and Fuzzy (similarity-based)
• Three row alignment modes: Positional, Key-based (match by key columns), or Content-based auto-alignment
• Column alignment: match columns by header name, even when column order differs between sheets
• Audit Metadata: compare cell notes, formulas, and data validation rules — not just values
• Per-sheet match statistics and aggregate scores
• Compare across multiple sheets simultaneously

🔎 DUPLICATE FINDER
Find duplicate rows within a single sheet or across multiple sheets:
• Self-compare mode: scan one sheet for internal duplicates
• Cross-sheet mode: find duplicates across 2 or more sheets
• Column-by-column mode: scan specific columns for duplicates within a single sheet
• Cell-by-cell dupe mode: positional cell-level duplicate detection
• Select which columns to match on (composite key support)
• Color-coded results: orange = duplicate, green = unique
• Shows which sheets and rows contain each match
• Merge Duplicates: one-click bulk removal with automatic undo snapshots

=== KEY FEATURES ===

✅ SCHEMA-AGNOSTIC — Works with any column layout. No fixed template required.

✅ AUTO-DETECT COLUMNS — Click one button and the add-on detects speaker, timestamp, transcript, and event columns from your headers. Supports camelCase, snake_case, and plain-English naming.

✅ COLOR-CODED DIFF VIEWER — A dedicated output sheet with color-coded rows, inline text diffs (bold green = added, red strikethrough = removed), and collapsible sections.

✅ QA METRICS — Word Error Rate (WER), Character Error Rate (CER), Segment Error Rate (SER), and a dynamic Composite Quality Score — computed automatically.

✅ EXPORTABLE QA REPORT — Generate a clean, shareable report sheet with all metrics, change logs, and metadata — perfect for team reviews and audits.

✅ SNAPSHOT WORKFLOW — Commit a snapshot of your original data before editing. Run the diff at any time to see exactly what changed.

✅ COMPARISON SCENARIOS — Save and reload named presets for different workflows (e.g. "QA Review", "Dedup Import", "Cell Audit"). Switch between configurations instantly.

✅ CUSTOM TRANSFORM RULES — Define your own find/replace rules (plain text or regex) applied before comparison. Rules are independent per comparison mode — tailor transforms for Structural vs. Cell-by-Cell vs. Duplicate Finder independently.

✅ IGNORE COLUMNS — Exclude specific columns by name from any comparison. Works cross-sheet — even when column positions differ between sheets.

✅ CROSS-SPREADSHEET IMPORT — Browse your Google Drive™ directly from the Compare Picker to import sheets from other files. Compare data across separate spreadsheets without manual copy-pasting.

✅ COMPARE PICKER — A visual sheet selector with batch complexity estimates. Pick your baseline and compare sheets, see row counts, and get an estimated run time before launching.

✅ SAFE CHUNKED EXECUTION — Large datasets are automatically processed in time-safe chunks with real-time progress tracking. 
Cancel mid-run and choose to keep partial results, discard, or resume.

✅ MULTI-LANGUAGE SUPPORT — Full Unicode normalization across 6 numeral systems (Arabic, Persian, Devanagari, Bengali, Thai, fullwidth). Optional diacritics stripping for accent-insensitive comparison.

✅ PERFORMANCE OPTIMIZED — Batch rendering (5–10× faster), configurable output row limits, auto-hide unchanged rows for large datasets.

✅ UNDO SUPPORT — Duplicate removal auto-creates backup snapshots. Restore with one click if needed.

✅ CONFIGURABLE — Similarity thresholds, column mapping, row alignment modes, split/merge toggles, inline diff toggle, max output rows, hide unchanged rows, output column visibility, custom transforms, ignore columns — all adjustable in the settings sidebar.

=== PRICING ===

• 7-day free trial — unlimited access to all features
• Free tier — 10 comparisons per month
• Pro — monthly, yearly, or lifetime subscription for unlimited usage

=== WHO IS THIS FOR? ===

• Localization teams — compare original vs. post-edited transcripts
• Translation reviewers — diff source vs. target language versions
• Financial analysts — reconcile versions of reports and budgets
• Data teams — audit spreadsheet changes, find duplicates, and clean data
• QA engineers — compare formulas, notes, and validation rules across versions
• Project managers — track what changed between deliverable versions
• Anyone who needs to compare two (or more) sheets in Google Sheets™

=== GETTING STARTED ===

1. Install the add-on
2. Open any spreadsheet → Extensions → SheetDiff™
3. Click ⚙️ Settings → choose your comparison mode → Auto-Detect or manually map columns
4. For Structural Diff: click 📸 Commit Snapshot to save your original data
5. Click 🔍 Run Comparison → use the Compare Picker to select your sheets
6. Review the color-coded Diff Viewer → click 📄 Export Report for a shareable summary

=== SUPPORT & LINKS ===

🌐 Developer: mohamedyaakoubi.live
📧 Contact: amirrak8@gmail.com
Developed by Mohamed Yaakoubi.

Google Sheets™ and Google Drive™ are trademarks of Google LLC.