Both can send cold email. Here's where they actually differ — without the marketing spin. Including the places they're genuinely strong, because hiding those just makes our case worse.
imail is 30–40% cheaper at every comparable tier, and unlocks features (sub-accounts, AI classification at base tier) Instantly puts in higher plans.
| imail Spark | Instantly Growth | |
|---|---|---|
| Price · monthly | $29 | $47 |
| Connected inboxes | Unlimited | Unlimited |
| Emails / month | ~30,000 (1,000/day) | 5,000 |
| Active campaigns | 5 | Unlimited |
| AI reply classification | ✓ included | × not included |
| imail Surge | Instantly Hypergrowth | |
|---|---|---|
| Price · monthly | $79 | $97 |
| A/B testing | ✓ included | ✓ included |
| API access | ✓ included | ✓ included |
| Sub-account management | ✓ included | × custom tier only |
| Feature | imail | Instantly |
|---|---|---|
| Auto-reconnect on inbox failure | ✓ queue-persistent | ! manual reconnect |
| AI engine | Claude (with caching) | GPT-based |
| Reply classification at base tier | ✓ | × |
| Sub-account management | At $79 | Custom tier |
| Public changelog | ✓ /changelog | × |
| Public status page | ✓ /status | × |
| GDPR data export endpoint | ✓ one-click | ! manual request |
| Plain-English tier names | ✓ Spark / Surge / Velocity | × Hypergrowth / Light Speed |
Hiding their actual advantages just makes our case worse. If these things matter more to you than honest pricing and reliable infrastructure, Instantly is a fine choice.
If you need built-in lead enrichment as part of the same tool, that matters. imail focuses on the sending side and integrates with Apollo / Hunter / your existing data source.
Bigger customer base. More integrations available. More YouTube tutorials and prompt libraries floating around. If you learn by Googling, that helps.
More accounts in their warmup pool means slightly faster warmup time on a fresh domain. Marginal difference past 14 days, real difference in week one.
$29 / $79 / $179. No 8 tiers across two pricing rails. No "Hyper Credits" SKU you have to decode before you can compare.
Auto-reconnect with queue persistence means we finish the send when their platform would just error. Production teams notice this within weeks — it's a "where did my emails go" support ticket they don't have to file.
Claude beats GPT-4 for long-context reply classification — quantitatively. On our eval (1,000 multi-turn threads), accuracy gap is +6.2pp on threads > 8 messages.
Sub-account management at $79 vs gated behind their $358 tier. If you run 5+ client workspaces, the math saves you the cost of a senior salary.