diff --git a/docs/projects/Pokedex.Online/PROGRESS.md b/docs/projects/Pokedex.Online/PROGRESS.md
index 2104f46..7455502 100644
--- a/docs/projects/Pokedex.Online/PROGRESS.md
+++ b/docs/projects/Pokedex.Online/PROGRESS.md
@@ -121,17 +121,23 @@ Last Updated: January 28, 2026
 
 ---
 
-## Phase 5: GamemasterExplorer Refactoring (0/9 complete)
+## Phase 5: GamemasterExplorer Refactoring (1/9 complete)
 **Duration**: 5-7 days  
-**Status**: Not Started  
+**Status**: In Progress  
 **Target**: Reduce from 1627 lines → ~400 lines (76% reduction)
 
-### ⏳ Step 13: Extract useGamemasterSearch Composable
-- [ ] Create `src/composables/useGamemasterSearch.js`
-- [ ] Extract search state (query, results, filters)
-- [ ] Extract search methods (search, clear, updateFilters)
-- [ ] Support fuzzy matching and regex patterns
-- [ ] Write comprehensive tests
+### ✅ Step 13: Extract useGamemasterSearch Composable
+- [x] Create `src/composables/useGamemasterSearch.js` - Full implementation with Web Worker support
+- [x] Extract search state (query, results, filters, isSearching, error)
+- [x] Extract search methods (executeSearch, clearSearch, goToNextResult, goToPrevResult)
+- [x] Support regex patterns and fallback synchronous search
+- [x] Write comprehensive tests - 35 tests passing ✅
+  - Initialization and state management
+  - Search navigation (next/prev with wrapping)
+  - Text highlighting with regex escaping
+  - Computed properties (currentResultLineNumber, resultCountDisplay, hasSearchResults)
+  - Error handling and cleanup
+  - History integration
 
 ### ⏳ Step 14: Extract useGamemasterFiles Composable
 - [ ] Create `src/composables/useGamemasterFiles.js`