Nitrosend vs Constant Contact.

Unlimited contacts, sends not tied to your list, agent-native, published price at scale.

TL;DR

Constant Contact is email and digital marketing for small businesses and nonprofits. Events with registration and ticketing, US SMS, social posting, ads, and landing pages sit in the same product as the email that promotes them, sold on being easy to run and on there being a phone number to call. You're priced on the contacts you hold. If you use the events half or the phone-support half, that bundle is the argument, and it's a good one.

A bundle can add an assistant, but the screen stays the unit of work. Nitrosend is an AI-native email platform, and two things underneath it are built differently. The meter: contacts are unlimited on every plan including Free, and the monthly send allowance isn't a multiple of your list, so volume and list size are two decisions rather than one. The architecture: an agent builds the segment, sends the campaign, and reads the result, because every capability is an MCP tool before it's a screen.

Small teams comparing the contact-priced bundles usually read the Courier comparison and the Dotdigital comparison beside this one, at the two ends of the range, and the Drip comparison covers the ecommerce-focused version of the same meter.

Pricing math

What you actually pay.

Constant Contact charges on the contacts you hold, and the monthly send allowance is a multiple of that count: 10x on Lite, 12x on Standard, and 24x on Premium. So list size and send volume can't be sized separately there. Nitrosend charges on what you send and never counts contacts, so each column below answers on its own meter. Monthly billing, in USD, before Constant Contact's 15% annual discount.

Scenario	Nitrosend	Constant Contact
Free	8,000 emails to start, then 500/mo forever. Unlimited contacts, 1 seat, full MCP, API, and CLI	No free plan. A 14-day trial, then Lite from $12/mo at 500 contacts: 5,000 emails, one user, one automation
500 contacts, 20,000 emails/mo	$20 Pro: 20,000 emails, 3 seats, BYO sending and AI keys	At 500 contacts the allowance tops out at 12,000 emails on $80 Premium (24x), and the remaining 8,000 bill as overage at $0.002 an email
5,000 contacts, ~100,000 emails/mo	$100 Ultra: 125,000 emails, 5 brands, 10 seats	$80 Lite allows 50,000 and $110 Standard allows 60,000. $200 Premium is the first rung that reaches 120,000
50,000 contacts, 500,000 emails/mo	$300 Enterprise: 500K to 4M+ emails at a published price, with SSO and SAML	$430 Lite covers exactly 500,000 sends on a single-user plan. $460 Standard covers 600,000 and $575 Premium covers 1.2M

Prices accurate as of August 2026. Check vendor sites for current rates.

Migration

How to switch (or run both).

Constant Contact keeps sending while you move, and if you run event registration, ticketing, or US SMS, those stay exactly where they are.

Add and verify your sending domain in Nitrosend. DKIM and SPF records sit alongside Constant Contact's, so both platforms can send from the same domain for as long as the overlap lasts.
Export your contacts with their custom fields. From the UI that's the Contacts page filtered to a list, segment, or tag, then Actions and Export selection. Scripted, it's POST /v3/activities/contact_exports followed by GET /v3/contact_exports/{file_export_id}, which carries every contact field including the custom ones by default. Import them with nitro_import_contacts.
Export the unsubscribes and removals separately and load them as suppression before your first send. The export filters on status, so the people who opted out of your list travel with it. This is the step that goes wrong most often on any migration, and it goes wrong quietly.
Move one low-stakes message type first, a receipt or a reminder, with nitro_send_message, and watch it for a week before a campaign follows it. Rebuild automations as flows with nitro_compose_flow.
Decide what carries your reputation, then close the account on your own schedule. BYO sending keys on Pro and above route mail through Amazon SES, Resend, Postmark, Mailgun, or SendGrid, and Constant Contact's own pool isn't one of them, so a sender leaving it is warming a new path whichever platform it lands on. What travels with you is the domain and its authentication history. Cancellation there runs through the support line rather than a button, so start it before your next billing date rather than after your last send.

Honest credit

What Constant Contact does well.

Picking a tool is about fit. Here's what Constant Contact is genuinely good at.

Phone support on every paid plan.
Event marketing inside the same product as the email that promotes it: guest lists, registration, promotion, and ticket sales.
A long deliverability track record.
Unsubscribed contacts stop being billable, so a list that churns doesn't keep charging for addresses that can't be mailed.
SMS against the same contact record for US senders, with 500 messages a month included on Premium.
More than 300 apps and integrations, covering the tools a local business already runs.
Up to 30% off an annual subscription for nonprofits, on a product that already carries events and donations.
In market since 1995, so the agency, bookkeeper, or volunteer coordinator a small organization already works with has used it.
A documented, scriptable way out: the V3 API exports every contact field including custom fields, filtered by list, segment, tag, or status.

What Nitrosend adds

Where we think we're better.

Contact count is never a billing input, on Free as much as on Enterprise, so a list that grows without being mailed never moves the bill.
You size send volume on its own, so the plan you need follows the mail you actually send rather than the addresses you're holding.
A published price from 500,000 to over 4,000,000 emails a month, where the ladder usually turns into a sales call.
Campaigns and transactional sending in one product, so receipts and password resets don't need a second vendor beside the marketing tool.
MCP-first is an architecture, not an integration: the API endpoint and the MCP tool come first, so an agent gets the whole product rather than the slice somebody remembered to expose.
Constant Contact's agent surface is its V3 REST API, and the MCP servers reaching it today are third-party wrappers over it.
Deliverability, billing, tests, and approvals are tools here, and they're the four edges that usually stop an automation dead.
BYO sending keys on Pro and above route your mail through Amazon SES, Resend, Postmark, Mailgun, or SendGrid, on the domain and IP you already warmed.
Routing through a transport you already warmed keeps the move reversible, where switching platforms otherwise means switching sending reputation on the same day, when the two failures look identical.

Use case fit

When to pick which.

Pick Constant Contact if

You run events and want registration, ticketing, and the invitation that promotes them in one tool. A phone number with a person on the end of it points the same way, and so does sending US SMS beside your email against a single contact record. Nonprofits get up to 30% off an annual subscription here. None of those are close calls.

Pick Nitrosend if

Email is the channel your program runs on and your list is much larger than your send volume, so you're tired of buying contact capacity to unlock sends. It's the right call too when campaigns and transactional mail should come out of one product rather than two vendors, and when you want the platform to answer to an agent end to end, including the billing, testing, and approval steps that usually send someone back to a dashboard.

Constant Contact vs Nitrosend - common questions.

Can Nitrosend replace Constant Contact?

For the email half, yes, and it transfers cleanly if you already work through an agent. Campaigns, flows, segments, templates, contacts, and transactional sending are each an MCP tool and an API endpoint here rather than a screen with an assistant added to it, so the agent that runs the rest of your stack runs your email too, and transactional isn't a separate product with a separate bill. Event registration, ticketing, and US SMS stay with Constant Contact, so a team running those either keeps it for them or splits the stack deliberately.

Does Constant Contact have a free plan?

No. The entry route is a 14-day trial, and Lite then starts at $12 a month for 500 contacts with a 5,000-email allowance. Nitrosend's free plan is free permanently: unlimited contacts, 8,000 emails to start, then 500 a month after that, with the full MCP server, API, and CLI on it.

How many emails can I send on Constant Contact?

It depends on how many contacts you're paying for, because each plan multiplies that number: Lite by 10, Standard by 12, and Premium by 24. A 500-contact list gets 5,000, 6,000, or 12,000 emails a month depending on the plan. Mail past the allowance still goes out and bills at $0.002 an email, which is $2 for every 1,000 sends over.

Can I keep sending from Constant Contact while I move?

Yes, during the overlap. Both platforms can authenticate against the same domain, so you can move one message type at a time and leave the rest sending. What you can't do is point Nitrosend at their transport: BYO sending keys cover Amazon SES, Resend, Postmark, Mailgun, and SendGrid. Time the ending as well, because cancellation runs through their support line rather than a button.

Start with the free tier.

8,000 emails to start, then 500 a month, unlimited contacts, full MCP, API and CLI access. No credit card.