| Ixquick Toolbar | | - | | |
| Iwara Source Downloader | | - | | |
| InterfaceLIFT NewTab | | - | | |
| Integrated Google Calendar | | - | | |
| Integrated GMail | | - | | |
| Install Collection | | - | | |
| InstaRead | | - | | |
| Insite Search | | - | | |
| Inquisitor | | - | | |
| InoReader RSS Reader extension | | - | | |
| InoReader Companion | | - | | |
| InlineThumbnail | | - | | |
| Inline Translator | | - | | |
| Inline Search | | - | | |
| Inline Google Search | | - | | |
| Inline Google Definitions | | - | | |
| In The News | | - | | |
| Imgur to Filmot | | - | | |
| Imgur Uploader | | - | | |
| Imgrill Uploader | | - | | |
| Imgchili.com Upload | | - | | |
| ImgMoney Upload Extension | | - | | |
| ImgFly.eu Free Image Hosting | | - | | |
| Imagus | | - | | |
| ImageSearch | | - | | |
| ImageFolks | | - | | |
| Image reverse search | | - | | |
| Image Search Pro | | - | | |
| Image Search Options | | - | | |
| Image Search | | - | | |
| Image Lookup | | - | | |
| Image GOku Image Viewer | | - | | |
| ImTranslator | | - | | |
| IYH Launcher | | - | | |
| IP to Geolocation | | - | | |
| IP Address and Domain Information | | - | | |
| IP Address Lookup | | - | | |
| IMDb rating | | - | | |
| IMDb Info | | - | | |
| IMDB Autofocus On Searchform | | - | | |
| IMDB Search | | - | | |
| I REC ： +1 and Like in just a click | | - | | |
| I Like Google! | | - | | |
| Hyperwords(tm) | | - | | |
| HyperTranslate | | - | | |
| Hover Translate | | - | | |
| Hotmail Watcher | | - | | |
| Host Pic.Org | | - | | |
| HootSuite | | - | | |
| HootBar | | - | | |