Add performance metric column for Ruby 4.0.0, and conclusion

Author: jvmvik

README.md

@@ -1013,18 +1013,19 @@ see: [https://serpapi.com/yelp-search-api](https://serpapi.com/yelp-search-api)
 
 ### Ruby 3.4.4 vs Ruby 2.7.8 Performance
 
-| Metric | Ruby 2.7.8 | Ruby 3.4.4 | Ruby 4.0.0 | Improvement (3.4.4 vs 2.7.8) |
-|--------|------------|------------|------------|------------------------------|
-| **SerpApi Non-Persistent** | 100.93 req/s | 114.97 req/s | 120.09 req/s | **+13.9%** |
-| **SerpApi Persistent** | 226.82 req/s | 255.07 req/s | 296.05 req/s | **+12.4%** |
-| **HTTP.rb Non-Persistent** | 270.62 req/s | 294.01 req/s | 319.81 req/s | **+8.6%** |
-| **HTTP.rb Persistent** | 347.04 req/s | 570.95 req/s | 456.93 req/s | **+64.5%** |
+| Metric | Ruby 2.7.8 | Ruby 3.4.4 | Ruby 4.0.0 | Improvement (3.4.4 vs 2.7.8) | Improvement (4.0.0 vs 3.4.4) |
+|--------|------------|------------|------------|------------------------------|------------------------------|
+| **SerpApi Non-Persistent** | 100.93 req/s | 114.97 req/s | 120.09 req/s | **+13.9%** | **+4.5%** |
+| **SerpApi Persistent** | 226.82 req/s | 255.07 req/s | 296.05 req/s | **+12.4%** | **+16.1%** |
+| **HTTP.rb Non-Persistent** | 270.62 req/s | 294.01 req/s | 319.81 req/s | **+8.6%** | **+8.8%** |
+| **HTTP.rb Persistent** | 347.04 req/s | 570.95 req/s | 456.93 req/s | **+64.5%** | **-20.0%** |
 
 ### Key Takeaways
 1. **Upgrade to Ruby 3.4.4**: Clear performance benefits across all scenarios
 2. **Use Persistent Connections**: 2x+ performance improvement in most cases
 3. **HTTP.rb Performance**: Particularly benefits from Ruby 3.4.4 with persistent connections
 4. **SerpApi Optimization**: Shows consistent ~2.2x improvement with persistent connections regardless of Ruby version
+5. **Ruby 4.0.0 Performance**: Shows mixed results with some regressions compared to 3.4.4, particularly for HTTP.rb persistent connections. Ruby 4.0.0 was just released for Christmas 2025, and HTTP.rb has not been optimized for it yet.
 
 The older library (google-search-results-ruby) was performing at 55 req/s on Ruby 2.7.8, which is 2x slower than the current version (serpapi-ruby) on Ruby 3.4.4.
 

README.md.erb

@@ -494,18 +494,19 @@ see: [https://serpapi.com/yelp-search-api](https://serpapi.com/yelp-search-api)
 
 ### Ruby 3.4.4 vs Ruby 2.7.8 Performance
 
-| Metric | Ruby 2.7.8 | Ruby 3.4.4 | Ruby 4.0.0 | Improvement (3.4.4 vs 2.7.8) |
-|--------|------------|------------|------------|------------------------------|
-| **SerpApi Non-Persistent** | 100.93 req/s | 114.97 req/s | 120.09 req/s | **+13.9%** |
-| **SerpApi Persistent** | 226.82 req/s | 255.07 req/s | 296.05 req/s | **+12.4%** |
-| **HTTP.rb Non-Persistent** | 270.62 req/s | 294.01 req/s | 319.81 req/s | **+8.6%** |
-| **HTTP.rb Persistent** | 347.04 req/s | 570.95 req/s | 456.93 req/s | **+64.5%** |
+| Metric | Ruby 2.7.8 | Ruby 3.4.4 | Ruby 4.0.0 | Improvement (3.4.4 vs 2.7.8) | Improvement (4.0.0 vs 3.4.4) |
+|--------|------------|------------|------------|------------------------------|------------------------------|
+| **SerpApi Non-Persistent** | 100.93 req/s | 114.97 req/s | 120.09 req/s | **+13.9%** | **+4.5%** |
+| **SerpApi Persistent** | 226.82 req/s | 255.07 req/s | 296.05 req/s | **+12.4%** | **+16.1%** |
+| **HTTP.rb Non-Persistent** | 270.62 req/s | 294.01 req/s | 319.81 req/s | **+8.6%** | **+8.8%** |
+| **HTTP.rb Persistent** | 347.04 req/s | 570.95 req/s | 456.93 req/s | **+64.5%** | **-20.0%** |
 
 ### Key Takeaways
 1. **Upgrade to Ruby 3.4.4**: Clear performance benefits across all scenarios
 2. **Use Persistent Connections**: 2x+ performance improvement in most cases
 3. **HTTP.rb Performance**: Particularly benefits from Ruby 3.4.4 with persistent connections
 4. **SerpApi Optimization**: Shows consistent ~2.2x improvement with persistent connections regardless of Ruby version
+5. **Ruby 4.0.0 Performance**: Shows mixed results with some regressions compared to 3.4.4, particularly for HTTP.rb persistent connections. Ruby 4.0.0 was just released for Christmas 2025, and HTTP.rb has not been optimized for it yet.
 
 The older library (google-search-results-ruby) was performing at 55 req/s on Ruby 2.7.8, which is 2x slower than the current version (serpapi-ruby) on Ruby 3.4.4.