Instantly API review
Best for unlimited mailboxes and warmup
GET https://api.instantly.ai/api/v2/accounts?limit=5 Authorization: Bearer $INSTANTLY_API_KEY # 100 req/s and 6,000/min, whichever you hit first # shared across v1, v2 and every key in the workspace # unlimited email accounts on every Outreach plan
The thing to understand about Instantly before anything else is that it is two products with two subscriptions. The Outreach half gives you unlimited email accounts and unlimited warmup from $47 a month, metered on emails sent and contacts uploaded rather than on mailboxes. The Credits half, also from $47, buys access to a 450 million contact database, waterfall work email enrichment across five or more providers, and a set of AI research agents. The bundles Instantly advertises, Starter at $94 and Scale at $194 a month, are simply the two halves added together.
That split is unusual and it is the main reason to choose Instantly. Most sending tools charge per mailbox, which quietly sets the ceiling on how much infrastructure you can run; Instantly charges for volume and lets you attach as many sending accounts as you want, with warmup included on each. If you are running a cold email operation across dozens of domains, that is a structurally different bill.
The Instantly API is a straightforward REST surface at api.instantly.ai, currently on v2, with Bearer authentication and scoped keys. The rate limits are generous and have one wrinkle worth reading carefully before you design a backfill, because the two published numbers are the same rate expressed twice.
The rest of the category is in the Sending APIs listing.
What the two halves actually buy
Instantly publishes the plans separately and the bundles as a combination, which makes it easy to over-buy. These are the published monthly figures.
| Plan | What it is | Published price | What you get |
|---|---|---|---|
| Growth, Outreach | The sending half | $47/mo | Unlimited email accounts, unlimited warmup, 1,000 uploaded contacts, 5,000 emails a month |
| Growth, Credits | The data half | $47/mo | 1,500 credits, the 450M contact database, waterfall work email enrichment, AI research agents |
| Starter bundle | Both halves | $94/mo | 5,000 emails, 1,000 uploaded contacts, 1,500 credits |
| Scale bundle | Both halves | $194/mo | 100,000 emails, 25,000 uploaded contacts, 5,000 credits, AI Reply Agent |
| Hypergrowth, Outreach | The sending half | $358/mo | Everything in Growth at higher volume |
| Hypergrowth, Credits | The data half | $197/mo | 5,000 credits a month |
| Top bundle | Both halves | $555/mo | 500,000 emails a month, 100,000 uploaded contacts |
The arithmetic is worth doing in both directions. Starter at $94 is exactly the two $47 plans, so bundling saves nothing at the bottom; it is a convenience, not a discount. At the top, Hypergrowth Outreach at $358 plus Hypergrowth Credits at $197 is $555, which is the advertised top bundle, so the same holds.
What that means in practice is that you should buy only the half you need. A team with its own data source can take Outreach alone at $47 and never pay for credits, and a team that only wants the database can take Credits alone without paying for sending it will not do.
Every Outreach plan carries unlimited email accounts and unlimited warmup, which is the line that separates Instantly from most of its competitors. The meter is on emails sent and contacts uploaded instead. For a cold outbound operation that spreads sending across many domains and inboxes to protect deliverability, charging by volume rather than by mailbox removes the thing that usually caps the strategy. It also means the comparison against a per-mailbox competitor depends entirely on how many inboxes you intend to run, so count them before pricing anything.
Instantly API pricing, plan by plan
Instantly API pricing does not exist as a separate line. API access comes with the subscription, and what you are really buying is the volume allowance on whichever half, or both halves, you subscribe to.
Outreach only
- Unlimited email accounts and warmup
- 5,000 emails, 1,000 uploaded contacts
- No database access
Credits only
- 1,500 credits a month
- 450M contact database and waterfall enrichment
- No sending
Starter bundle
- Both halves, at the same combined price
- 5,000 emails, 1,000 contacts, 1,500 credits
- AI Sales Agent
Scale bundle
- 100,000 emails, 25,000 uploaded contacts
- 5,000 credits a month
- AI Reply Agent and premium live support
There is no free tier. Prices above are the monthly figures Instantly publishes, and the top bundle runs to $555 a month for 500,000 emails and 100,000 uploaded contacts. Because the halves are separately purchasable, the honest way to size this is to price the sending volume and the data volume independently and then check whether the bundle beats the sum, which at the published figures it does not.
The two meters move at very different rates between tiers. Going from Starter to Scale multiplies emails by 20, from 5,000 to 100,000, and uploaded contacts by 25, from 1,000 to 25,000, for roughly twice the money. If your sequences are long, the email count is generous and the contact count is what binds; if you are sending one or two touches to large lists, the reverse. Work out which of the two you will exhaust first, because the plan that looks expensive on one meter is usually the cheap one on the other.
Two numbers that are the same rate
Instantly API rate limits are published as two figures: no more than 100 requests per second, and no more than 6,000 requests per minute. Requests are blocked if you reach either one, and both are shared between API v1 and v2 and across the entire workspace, no matter how many API keys it holds.
| Limit | Figure | What it means |
|---|---|---|
| Per second | 100 req/s | The burst ceiling. |
| Per minute | 6,000 req/min | Exactly 100 a second sustained, so there is no burst allowance above the per-second rate. |
| Scope | Whole workspace | Shared across v1 and v2 and every key, so a second integration eats into the first. |
| On exceeding | 429 | Requests fail rather than queue. |
Instantly's own guidance
Published on the rate limit page.
- Run scheduled automations two to four times a day rather than once, so the requests spread out.
- Batch updates in groups of 100 with a two second wait between batches.
- For 10,000 lead updates that is 100 batches, so a little over three minutes of wall clock.
- The documented approach is throttling on your side rather than retrying after a 429.
What the shared scope means
One budget for everything.
- Multiple API keys do not multiply the allowance; they divide it.
- A v1 integration you forgot about still consumes the same budget as v2.
- An unattended sync and a human-triggered action compete for the same 100 a second.
- There is no documented per-key quota, so one noisy integration can starve another.
It is worth being explicit because it changes how you design: 6,000 requests a minute is exactly 100 a second sustained, so Instantly is not offering a burst allowance on top of a sustained rate the way most APIs do. You get 100 a second and you may not bank the unused ones. A job that wants to fire 3,000 requests in ten seconds is inside the per-minute limit and will still be blocked by the per-second one. Design to the per-second figure and treat the per-minute number as confirmation rather than headroom.
How to create an Instantly API key
Instantly uses scoped API keys with Bearer authentication, which is a better arrangement than the single all-powerful key several competitors ship, and the key is shown once.
Creating the key
Scoped at creation.
- Open Settings, then Integrations, then API Keys, and create an API v2 key.
- Select the scopes the integration actually needs at the point of creation.
- Copy it immediately: Instantly displays the key once and you cannot view it again.
- Send it as Authorization: Bearer YOUR_API_KEY.
Practical notes
What the scoping does and does not do.
- Scopes limit what a key can do, which makes a per-integration key worth the effort.
- They do not limit how much it can consume: the rate limit is per workspace, not per key.
- A key belongs to a workspace, so moving an integration between workspaces means a new key.
- There is no documented expiry, so rotate on a schedule rather than waiting for a prompt.
Where the Instantly API documentation lives
The Instantly API docs live at developer.instantly.ai, and the documentation is built on Mintlify, which means appending .md to any page returns the Markdown and there is an llms.txt index of every page. That is the fastest route in for an agent, and worth knowing because the older developer URLs now return a styled 404 rather than a redirect.
| Surface | Where | What it answers |
|---|---|---|
| Quickstart | developer.instantly.ai/quickstart | Creating a key and the first authenticated call. |
| Rate limits | developer.instantly.ai/getting-started/rate-limit | The two figures, the 429, and the batching guidance. |
| API base | api.instantly.ai/api/v2/ | Where the Instantly API v2 requests go. |
| Agent index | developer.instantly.ai/llms.txt | Every documentation page, listed for a model to fetch. |
| Key management | app.instantly.ai, Settings then Integrations | Where the Instantly API key is created and scoped. |
Both v1 and v2 are live and they share one rate limit, so a migration does not buy you headroom. There is no official SDK, so integrations are direct REST calls, and the documentation is explicit that you should restructure your code to fit the limits rather than expecting the limits to flex.
Instantly also ships an MCP server, and it is on the MCP page with the others in this directory.
Instantly's own product demo
Instantly publishes this on its own channel, so it is Instantly's account of Instantly, not ours. It is here because a rate card cannot show you the thing moving, and a few minutes of the product is faster than any paragraph on this page at telling you whether the shape of it fits yours.
YouTube · Instantly Full Instantly.ai Tutorial 2025 (Best Cold Email Software) 37:25 · Published September 2025Thirty seven minutes, which is a commitment, and it is the only current full walkthrough Instantly publishes. It is a cold email tutorial rather than an API tour, so watch it to decide whether the platform fits, then read the endpoint table above for what driving it costs.
Published 7 September 2025 on Instantly, the channel Instantly's own pages link to, and read on 13 October 2026. Nothing in it is a source for a price or a limit on this page: every figure in the tables above comes from an Instantly page.
Strengths and limits
Instantly is built for volume cold outbound and priced for it, with the honesty of publishing every figure.
What it does well
- Unlimited email accounts and unlimited warmup on every Outreach plan.
- Sending and data sold separately, so you can buy only the half you need.
- Every price is published, including the top bundle at $555 a month.
- 100 requests a second is generous for a sending platform.
- Scoped API keys rather than one key with full access.
- Documentation on Mintlify with an llms.txt index, which agents can read directly.
- A 450M contact database with waterfall enrichment, if you take the Credits half.
Where it falls short
- No free tier at all, and no trial credits published.
- The rate limit is per workspace, so extra keys divide it rather than multiply it.
- The two published limits are the same rate, so there is no burst allowance.
- Bundles are exactly the sum of the halves, so they are convenience rather than value.
- A client that cannot send headers takes the MCP key in the URL path, which puts the key in any config file you share.
- No official SDK, so every integration is raw REST.
- Older developer URLs 404 rather than redirecting, which wastes time.
Where Instantly data comes from, and what you may do with it
The question that arrives late and expensively is not how good the data is, it is who is allowed to hold it. These are the fields each one returns, the coverage it claims and the compliance it publishes.
| Provider | Fields returned | Coverage | Compliance | Redistribution |
|---|---|---|---|---|
| Instantly | Work email, Firmographics, Job postings, Intent and news | Global | GDPR DPA | Not stated |
None of these states a redistribution position on its pricing or docs pages. Internally that never matters. Put the rows in something your customers can see and it becomes the question your legal team asks first.
Two practical notes that apply to every provider on this page. A compliance badge describes the vendor, not your use of it, so a GDPR DPA does not give you a lawful basis for the outreach you send. And every one of these vendors runs its own opt-out, which means a person who asks you to delete their record has to be removed from your copy as well as from theirs.
If Instantly is not the answer
Four providers in the Sending APIs listing that solve the same problem differently. Each one is a trade, and the trade is named.
Smartlead
$39/moThe closest like-for-like on sending infrastructure, also API-first with unlimited mailboxes. The direct comparison if the sending half is what you are buying.
Apollo
$49/seat/moSequencing plus a much larger data platform behind one $49 seat, with a free plan at 900 credits a year. The move if you were buying both Instantly halves.
Salesloft
Quote onlyThe enterprise end of the same job, with a well documented cost-per-minute API. No published price, so expect a sales conversation.
Clay
$167/moNot a dedicated sender. Named because the Credits half is really enrichment, and if that is the part you value, a router in front of 150 providers does it properly.
The full set, organized by the reason people leave, is on the Instantly alternatives page.
Instantly against the obvious rival
Same rate cards, read side by side, with the arithmetic done on a worked volume rather than left to you: Apollo vs Instantly, Smartlead vs Instantly, Instantly vs Reply.io and Instantly vs lemlist.
The same again, against the rest of the field: Instantly vs Saleshandy, Instantly vs Outreach, Instantly vs QuickMail and Instantly vs Woodpecker.
Every pairing in the directory is on the compare hub.
Apollo vs Instantly
CompareOne seat that does everything against two subscriptions that each do one thing well.
Smartlead vs Instantly
CompareThe two senders that both give you unlimited mailboxes, gating the API in opposite ways.
Instantly vs Reply.io
CompareUnlimited mailboxes with no stated ceiling against unlimited mailboxes with a published ratio.
Before you build against it
Four things to settle first, each one read off Instantly's own pages. The ticks are remembered in this browser, so you can come back to a half-finished integration.
Who should actually buy this
Buy the Outreach half if you run cold email across many domains and inboxes. Unlimited email accounts with warmup included at $47 a month is the cheapest way in this directory to run that shape of operation, and the meter being on volume rather than mailboxes is exactly the right way round for deliverability work. Count your intended inboxes before comparing it against anything per-mailbox, because that single number decides the comparison.
Buy the Credits half only if you do not already have a data provider. At $47 for 1,500 credits it is reasonable, and the waterfall enrichment across five or more providers is genuinely useful, but most teams reading this directory already pay somebody for contact data and would be buying it twice. The bundles save nothing against the two halves, so there is no penalty for taking one.
On the API, design to 100 requests a second and remember the budget is the whole workspace. Instantly publishes its own guidance, batches of 100 with two seconds between them, and that is worth following rather than improving on. The thing to check before you commit is whether a second integration will be competing for the same budget, because nothing in the product will tell you that it is.
Unlimited mailboxes is only useful if the sequences are worth sending.
Infrastructure is the easy half of cold outbound. Frontal builds the signal, the targeting and the copy that make the sending worth paying for, inside your own stack.
Worked with 300+ companies. A senior operator runs your account.
Nothing worth quoting yet
The harvest this site runs searches Reddit for Instantly threads where the API itself is the subject, and it has not come back with a quote that survives the transcription rules yet. When one does, it lands here. Nothing on this page leans on an unquoted paraphrase.
Instantly API, answered
Is the Instantly API free?
No. No free tier. Outreach and Credits are sold separately from $47 each.
How much does the Instantly API cost?
Instantly starts at $47/mo. Billing is subscription and credit packs. Read from Instantly's own pricing page on 8 October 2026.
What are the Instantly API rate limits?
100 req/s and 6,000/min, shared across v1, v2 and every key in the workspace.
How do I get an Instantly API key?
Bearer token, from a scoped API v2 key in workspace settings. The current steps are in Instantly's own documentation, which is authoritative on anything that has changed since 8 October 2026.
Does Instantly have an MCP server?
Yes, at https://mcp.instantly.ai/mcp. It is listed with the others on the MCP page.