| Price from | $1.67/mo | Free |
| Free plan | — | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Web | Yes | Yes |
| Plans published | 6 | 1 |
| Spec score · Google Workspace for Marketing Software | 8.0 (#6) | 7.4 (#10) |
| Spec score · Mail Merge Software | 7.7 (#20) | 7.3 (#22) |
| Integrations | GMass lists a REST API, webhooks, Zapier, Google Sheets API, and SMTP relay as ways to connect with other apps and services. | Mergo works with Gmail and Google Sheets, and its features also use Google Docs, Drive, Contacts, and Forms. |
| Personalization | It supports mail merge personalization and conditional logic for campaigns. | It supports merge fields such as recipient first name and company, plus personalized attachments. |
| Support | GMass directs customers to read support guidelines and submit a support form to contact its support team. | Mergo provides support by email and says free-period support is provided on a best-effort basis. |
