16.5Era 4: WebDriver BiDi (2021-present)
The Best of Both Worlds
| Feature |
WebDriver |
CDP |
BiDi |
| Standardized |
W3C |
No (Chrome internal) |
W3C |
| Bidirectional |
No |
Yes |
Yes |
| Cross-browser |
Yes |
No (Chrome only) |
Yes |
| Events |
No |
Yes |
Yes |
| Transport |
HTTP |
WebSocket |
WebSocket |
| Stability |
Stable (standard) |
Unstable (internal) |
Stable (standard) |
How BiDi Solves CDP's Problems
- Standardized by W3C — Browser vendors commit to implementing it
- Cross-browser by design — Chrome, Firefox, Safari, Edge all participate
- Stable API contract — Changes go through a standards process
- Same power as CDP — Events, network, scripting, input
Current Browser Support (2026)
| Browser |
Status |
Notes |
| Chrome |
Full support |
Via chromedriver |
| Firefox |
Full support |
Native (no separate driver!) |
| Edge |
Full support |
Chromium-based |
| Safari |
Partial |
Improving each release |