COMPARISON
PostKnock vs PostGrid
PostGrid is a print-and-mail API. You give it an address and a template over HTTP and it posts a card — cheaply, reliably, at $0.902 for a 4×6. What it does not give you is a campaign: no sequence, no design tool a receptionist can use, no call list, no idea which patient hasn't been back in eighteen months. Those are things you would build on top of it. PostKnock is what that build produces, already finished.
| Feature | PostKnock | PostGrid |
|---|---|---|
| Who operates it | A business owner or front-desk staff | A developer, against an API |
| Code required | None | Yes — it is an API product |
| Per-piece 4×6 | $1.04 Free · $0.91 Pro | $0.902 (Starter, First Class) |
| Per-piece 6×9 | $1.07 Free · $0.94 Pro | $1.023 (Starter, First Class) |
| Volume cap on the free tier | None — Free plan has no monthly cap | 500 mailings/month on Starter |
| Published pricing above the free tier | ✓ Pro is $99/mo, on the pricing page | ✗ Enterprise is “Let’s talk” |
| Phone follow-up calls | ✓ Built-in per wave, script + daily queue | ✗ |
| Multi-wave sequences | ✓ Unlimited waves, non-responders advance automatically | ✗ You schedule the sends yourself |
| Design Studio: shuffle to a finished card | ✓ 4 style shells × 6 layouts, unlimited reshuffles | HTML templates you author |
| Ready-made playbooks (sequence + timing + call script) | ✓ 156 across 52 verticals | ✗ |
| Contact list management + dedupe | ✓ Import wizard, address validation, DNC handling | You manage the list in your own system |
| Address verification | ✓ Built into import and before every send | ✓ Sold as a separate API |
| Print proof before sending | ✓ Real print files, 4-point sign-off, blocks launch until approved | Render a preview via the API |
PostGrid figures read from postgrid.com/pricing-print-mail on 18 August 2026 and can change — confirm on their site. The rates quoted are US First Class on their Starter tier, which is capped at 500 mailings a month; their Enterprise tier is not publicly priced. PostKnock figures are our own published prices. All rates include printing and postage.
No monthly fee, no minimum, no time limit, and no card at signup. You fund a wallet before anything mails.
Where PostKnock goes further
The cheaper number is a component, not a product. $0.902 buys a card in an envelope-shaped API response. To get from there to a booked appointment somebody has to build list management, deduplication, a design tool, scheduling, wave logic, response tracking and a call workflow. That is months of engineering. If you have a team who will build it, PostGrid is a sensible substrate — and so is Lob, which we compare separately.
The free tier stops at 500 pieces a month. PostGrid's Starter plan caps at 500 mailings/month; past that you're into an Enterprise tier they price on a call. PostKnock's Free plan has no monthly cap: you pay $1.04 a card whether you send 20 or 20,000, and Pro's $0.91 is published rather than quoted.
Nobody at the front desk is going to call an API. The people who actually run a reactivation campaign at a dental practice are the office manager and the receptionist. PostKnock is built for them: pick a playbook, shuffle a design until it looks right, approve the proof, launch. PostGrid assumes a developer sits between them and the mail.
The calls have no equivalent. PostGrid prints and mails. It has no concept of a follow-up call, a script or a queue. In a local service business the postcard opens the door and the phone call books the work, which is the half PostKnock exists to automate.
Who is PostGrid best for?
PostGrid fits an engineering team adding mail to a product — an insurer sending policy documents, a fintech mailing statements, a SaaS triggering a card from a lifecycle event. The API is clean, address verification is strong, and at 500 pieces a month the Starter tier is free. If you are writing code and mail is one feature among many, buy the component.
Who is PostKnock best for?
PostKnock fits the owner of a dental practice, an HVAC company or a vet clinic who has a customer list and wants work booked from it. No engineer, no integration project: import the list, pick a playbook, approve the proof, and your front desk gets a call queue timed to when each card lands. You are buying the finished workflow rather than the plumbing.
Pricing comparison
PostGrid's Starter tier is $0/month up to 500 mailings, with US First Class postcards at $0.902 (4×6), $1.023 (6×9) and $1.289 (6×11). Above that, their Enterprise tier is quoted rather than published. PostKnock is Free at $0/mo ($1.04 / $1.07 / $1.29) with no volume cap, and Pro at $99/mo ($0.91 / $0.94 / $1.26).
On raw postage-plus-printing PostGrid is a little cheaper — about 14 cents a card against our free plan, and roughly break-even against Pro on a 4×6. The gap is the price of the software: sequences, the Design Studio, contact management, playbooks and the call queue. If you were going to build those anyway, the component is the cheaper path. If you were not, the finished product costs about a dime a card more.
Switching from PostGrid
Moving from PostGrid to PostKnock takes about 5 minutes:
- Export the contact list from whatever system holds it today, as a CSV
- Sign up for PostKnock (free, no credit card required)
- Import the CSV: PostKnock auto-maps name, address and phone columns and validates deliverability
- Pick a playbook for your industry, or design from scratch
- Approve the print proof and launch — no API keys, no deploy
A worked example: veterinary reminders
Plug your own numbers in. A clinic with 500 overdue patients running a 3-wave reminder sequence on PostKnock Pro:
- 500 patients × 3 waves = 1,500 postcards at the 4×6 Pro rate of $0.91 = $1,365, plus $99 for the month
- Phone follow-up calls after each wave, included in Pro
- Assume a 6% return rate → 30 appointments booked
- Assume an average visit is worth $250
- 30 × $250 = $7,500
The two assumptions above are ours, not measured results: response rate and customer value vary a lot by business, list quality and offer. Swap in your own figures before budgeting off this.
Frequently Asked Questions
Per piece, slightly. PostGrid's Starter tier is $0.902 for a 4×6 against our $1.04 free-plan rate and $0.91 on Pro, so on a 4×6 they are within a cent of our Pro price. Their Starter tier caps at 500 mailings a month and their Enterprise pricing is not published. The larger difference is that PostGrid is an API: the campaign software, contact management and call workflow are things you would build on top.
Yes, for the print-and-mail product — it is sold and documented as an API. PostKnock needs none: it is a web app a front-desk team uses directly, from importing a CSV to approving the print proof to working the call queue.
No. PostGrid prints and mails, and sells address verification alongside. There is no call queue, call script or follow-up workflow. PostKnock builds a call into each wave, timed to when the cards land, with the outcome tracked against the contact.