Compare
MailerSpark vs Instantly
Instantly is the cold outreach tool. MailerSpark is the cold outreach tool, the newsletter platform, the CRM, the Unibox, and the developer API — in one product, on the same contacts.
| Feature | Instantly | MailerSpark |
|---|---|---|
| Cold outreach sequences | ✓ | ✓ |
| Inbox rotation + warmup | ✓ | ✓ |
| Residential proxy rotation | ✓ | ✓ |
| Unibox (unified replies) | ✓ | ✓ |
| AI reply classification | ✓ (BounceIQ-style) | ✓ (OpenAI, Ollama, heuristic) |
| A/B subject testing (cold) | ✓ | ✓ |
| Stop on reply | ✓ | ✓ |
| Newsletter campaigns | ✗ | ✓ |
| Drag-and-drop builder | Limited | ✓ (11 block types) |
| Subscribers + double opt-in | ✗ | ✓ |
| Public subscribe forms + API | ✗ | ✓ |
| Automations (visual workflows) | ✗ | ✓ (Starter+) |
| Contact CRM + custom fields | Limited | ✓ |
| REST API | Limited | ✓ (Starter+) |
| Signed webhooks | Limited | ✓ (Growth+) |
| Self-hostable | ✗ | ✓ |
| BYO SMTP / Amazon SES | Limited | ✓ |
| Free plan | ✗ | 500 contacts, full features |
| Plans start at | $30/mo | $19/mo Starter · $49/mo Growth |
The honest take
Instantly is excellent at cold outreach — it was the tool that defined the category. Where it falls short: it's not a newsletter platform, the API is limited, and it doesn't have a real CRM.
MailerSpark covers the same cold-outreach ground (sequences, rotation, warmup, proxies, Unibox) and adds what most outbound teams also need: newsletters to their existing list, a CRM with custom fields, automations, and a real REST API. If you only do cold and Instantly is working, the switch may not be worth it. If you also send newsletters, or you want self-hosting, MailerSpark is the better fit.
Get started
Try MailerSpark on the free plan.
500 contacts, full feature set, no credit card.