Compared with Klaviyo Composer

Composer, Klaviyo’s marketing agent, is good at email and lives where your list already is. It drafts and audits inside Klaviyo, while your ad spend sits somewhere else.

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One situation, two ways

A discount the brand doesn’t give

A coffee roaster never discounts its coffee. 940 first-time buyers hadn’t placed a second order in 45 days.

Klaviyo

Asked to win them back, Composer drafts a campaign in minutes, following your brand guidance, and waits for your approval. Whether the draft offers a discount depends on that guidance, and on whoever approves it noticing.

Heraldic

The Reorders agent proposed 25% off a second order. Your content rules stopped it the moment it was proposed: “Offers a discount; none allowed.” Your note that day, “We don’t discount our coffee,” became guidance it picked up the next morning.

What it does well

Composer starts where your customers are: your profiles, orders and flows. It audits flows and campaigns on a schedule, drafts campaigns, flows and segments from a sentence, and publishes nothing until you approve it. For an email-first brand, that covers a lot.

Knowing your list: profiles, orders and every send they’ve had.
Drafting campaigns, flows and segments from a prompt, in the editor you already use.
Auditing your flows and campaigns on a schedule, around the clock.
Publishing nothing until you approve it.

Where it stops

1It drafts email, SMS and push. On ads, Composer shows which Meta ads bring back customers, and Klaviyo syncs segments to Meta, Google, TikTok and Pinterest as audiences. No Klaviyo page describes it setting budgets or bids.
2Klaviyo credits conversions to its messages, last touch by default. Its global holdout groups, which measure what your marketing as a whole added, need at least 400,000 profiles.
3Composer doesn’t send or publish without your sign-off, so every send it drafts waits for a person, however routine.
4Its reasoning shows as it works, and Klaviyo’s activity log records who changed what; both cover Klaviyo only.

Side by side, with cost.

Klaviyo Composer compared with Heraldic, row by row
Question	Klaviyo Composer	Heraldic
What it runs	Email, SMS and push in Klaviyo; on ads, Meta results in Composer and audiences synced to four ad platforms	Paid ads and lifecycle email, with an agent for each job
Judged on	Conversions Klaviyo credits to its messages (last touch, by default)	Your conversion events, each valued by what it’s worth to you
Who acts	Composer drafts and audits; you approve every send and every flow	Agents propose; for each kind of action, you choose whether it waits for you
Your limits	Your brand, voice and compliance guidance on every draft, and a person approves every send	Daily spend caps, a 20% limit on each change, and contact and content rules, checked before every change; no raise once the month’s cap is reached
The record	Citations and its reasoning as it works; Klaviyo’s activity log records changes	Every action, with who proposed it, why, the checks it passed and who approved it
Creative	Drafts emails, SMS, flows and segments	Images and copy drafted from your approved library; none runs until it’s approved
What it costs	Usage-based: every account gets $5 of Composer use a month free; a $20 monthly plan includes four times that.	Not set yet. Ad spend goes straight to the ad platforms

When to choose it instead

If email and SMS are most of your marketing and you want help drafting and auditing inside Klaviyo, with a person approving every send. Once ads and email share a budget and the same customers, you want one set of rules over both.

Questions about this comparison

Isn’t Composer enough?

For email and SMS, it may be. It knows your list and works where your sends already live. Agents here add your ads to the same picture: one set of limits across ads and email, results judged on your own conversion events, and every proposal and check on the record.

Whose numbers judge the email?

Your own conversion events, valued by what each is worth to you: the same events your ads are judged on. Each email send holds back a small group by default, and across sends, comparing the groups shows what email adds. When the groups are too small to tell, the report says so.

Can agents send without me?

Only if you let them. Sends start at You approve. Set them to Acts and notifies you, and the agent sends on its own, but contact limits, consent, suppression lists, quiet hours and banned phrases are still checked before every send.

Sources

What this page says about Klaviyo Composer comes from its own pages, checked November 1, 2026.

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