Kastr vs Bloomz: comparing the tiers, not the headline number
Bloomz's entry tier is $3 per student per year and ours is $3.50. If price is your only variable and your requirements fit their base tier, they are cheaper and you should buy from them. That sentence is in the first hundred words because everything after it depends on whether your requirements actually fit.
| Capability | Lowest Bloomz tier | Kastr |
|---|---|---|
| Announcements and two-way messaging | $3 | Included |
| Translation | $3 | Included — DeepL, previewable |
| Digital forms | $5 | Included |
| E-signature | $5 | Included |
| Voice calls | $5 | Included, with SMS failover into it |
| Automated notices | $5 | Rules configure; no engine fires them |
| Behaviour and PBIS | Available | Not built |
| Public REST API | Not published | 28 endpoints, org-scoped |
| Open-source CLI and MCP server | No | MIT licensed |
| Signed outbound webhooks | Not published | HMAC, SSRF-guarded, auto-disable |
| Cost preview before you send | No | Live, per channel |
| Volunteer group governance without admin rights | Not published | PTA volunteers admin their own group |
| Single sign-on | Yes | Magic link only |
| Attachments and photo sharing | Yes | Not built |
| Push notifications | Yes | Not built |
| Customers and references | Yes | None — pre-launch |
| Price increase capped in the contract | Price lock for term | 36 months fixed, then CPI-U or 5% |
Bloomz tier placements are from their published pricing page as of 4 August 2026. Five rows in this table go to Bloomz outright.
Find your real tier before you compare anything
Bloomz publishes four tiers at $3, $5, $7 and $9 per student per year, which is four more published numbers than most of this category manages. The comparison that matters is not $3 against $3.50; it is $3.50 against whichever tier contains the things your district actually does.
The boundary that catches most districts is at $5. Forms, e-signature, voice calls and automated notices all begin there. A district that sends permission slips, collects signatures, or makes automated phone calls — which is to say most districts — is comparing $5 to our $3.50, not $3.
Work it out honestly for your own requirements rather than taking either of our word for it. If your list genuinely stops at announcements, messaging and translation, their $3 tier is real and it is cheaper than us by fifty cents a student. For a 6,000-student district that is $3,000 a year, which is a real amount of money, and we would rather you spent it on something else than on a vendor whose extra capability you will not use.
Tier drift, which is the actual cost model
The risk with tiered pricing is not the tier you buy. It is the tier you end up in.
Take a 6,000-student district signing at $3 — $18,000 a year. In year two, the athletics department needs digital forms and the transport office wants automated voice calls for route changes. Both sit in the $5 tier, so the whole district moves to $5: $30,000. Over three years that is $18,000 plus $30,000 plus $30,000, a total of $78,000, against $63,000 at our flat $3.25 for that enrolment band. The district that saved $1,500 in year one paid $15,000 more across the term.
This is not a criticism of tiering, which is a legitimate way to price software. It is an argument for modelling your three-year total against the tier you will actually be in by year two, and for asking one specific question during the sales process: what triggers a tier change mid-term, and what does it cost? A district can be moved up a tier by one department's requirement.
Why we have one tier. Every feature is included at every enrolment band because a tiered vendor has a standing incentive to put the next thing you need one tier up. Removing our own ability to do that is worth more to a buyer than any individual feature, and it is the reason we have never shipped an add-on module.
On the beat-any-quote guarantee
Bloomz offers to beat any competing quote by ten per cent. It is a genuinely aggressive offer and it does one thing well: it lowers your year-one number. It is worth being precise about what it does not do.
- It is a discount off a tier, not a cap on a tier. If your requirements move you from $5 to $7, ten per cent off $7 is still more than $5.
- It applies to the quote you bring, not to your renewal. Ask directly whether the guarantee is available at renewal and get the answer in writing, because renewal is where the price pressure actually lives.
- It requires you to already have a competing quote, which in a category where most vendors publish nothing means running a full sales cycle with someone else first.
Our equivalent is structurally different and worth comparing on its own terms rather than as a bigger discount. §3.2 fixes the per-student rate for 36 months and caps year four onwards at the lesser of CPI-U or five per cent. It is not a better discount. It is a different instrument: a written ceiling on what the number can become, which is the thing a district cannot get by negotiating harder.
Where Bloomz is genuinely better, and one structural note
Five rows in the table above go to them and they are not trivia. Bloomz has a behaviour and PBIS module we have not built and do not plan to. They have single sign-on; we have a magic link and nothing else. They have attachments and photo sharing; we have none. They have push notifications; ours is a web app. And they have customers, which we do not — we are pre-launch with no references, no SOC 2 audit and no production deployments.
One more thing in their favour that few buyers would notice: Bloomz publishes an llms.txt, which is a deliberate, forward-looking piece of technical hygiene aimed at how AI assistants read a site. That is a company paying attention.
The structural note, offered as observation rather than argument: as of August 2026, 32 of 74 Bloomz pages canonicalise to their own homepage, including all six of their comparison pages and their pricing page. Their navigation anchors carry no href, so no internal link equity reaches those pages. The practical effect is that their own pricing page cannot rank for their own pricing query, which is why you are reading our explanation of their tiers rather than theirs. We have written a fuller breakdown for that reason, and we have tried to be accurate rather than convenient.
Questions people actually ask
Is Bloomz cheaper than Kastr?
At the entry tier, yes — $3 against our $3.50 per student per year. At the $5 tier, which is where forms, e-signature, voice and automated notices begin, no. Establish which tier your requirements land in, then compare the three-year total rather than year one.
What is actually included in Bloomz's $3 per student tier?
Announcements, two-way messaging and translation. Digital forms, e-signature, voice calls and automated notices are not in it — those start at $5. For many districts that moves the real comparison to the $5 tier immediately.
Does Bloomz's beat-any-quote guarantee apply at renewal?
Ask them and get it in writing. A discount against a competing quote lowers your entry price; it is not the same instrument as a contractual cap on annual increases, which is what protects you at renewal. Ours is §3.2: fixed 36 months, then the lesser of CPI-U or five per cent.
Why does Kastr not offer a cheaper entry tier?
Because a tiered vendor has a permanent incentive to place the next capability you need one tier above the one you bought, and we would rather not have that incentive. One rate, everything included, at every enrolment band. It costs us the price-sensitive end of the market and we accept that.
Which is better for a district that only needs basic messaging?
If your requirements genuinely stop at announcements, two-way messaging and translation, Bloomz's $3 tier is cheaper and we would tell you to take it. We become the better answer when forms, voice, an API or a written price cap enter the requirement list.
One price. Every feature. Locked for three years.
$3.50 per student per year under 5,000 students. No tiers, no add-on modules, no per-message fees. Published on the site because you should not have to book a call to learn a price.