Kastr vs Seesaw: portfolios and communications are not the same product
These are not competing products and a district that treats them as substitutes will make a bad decision either way. Seesaw is a student work portfolio with family messaging attached. Kastr is district notification infrastructure with no ability to send a photograph. Most elementary districts genuinely need both.
| Job to be done | Seesaw | Kastr |
|---|---|---|
| Collect and share student work over time | Core product | Nothing |
| Photos and video home to families | Core product | No attachments of any kind |
| Classroom-level family engagement | Strong | Not the design centre |
| Teacher-to-family messaging | Yes, with translation | Yes, with translation preview |
| District-wide notification to every family | Not built for it | Core product |
| Voice channel and SMS failover | No | Yes |
| Tamper-evident audit of official messages | Not published | SHA-256 hash chain, append-only |
| One identity across schools and roles | Class-scoped | Effective-dated multi-role |
| Public REST API and webhooks | Not published | 28 endpoints, signed webhooks |
| Published district price | Quote only | $3.50 / $3.25 / $3.00 |
| Grade band it fits | K–5 primarily | All, because notification is grade-agnostic |
Rows one to three go to Seesaw without qualification, and row two is absolute: Kastr has no upload path, no attachment storage, and no photo or video sharing anywhere in the product.
The four things districts pay for twice
Districts holding both a portfolio tool and a communications platform routinely duplicate spend, and it is almost always in the same four places. Deciding which contract carries each is a twenty-minute conversation that saves real money.
- Teacher-to-family messaging. Both products do it. Pick one and say so, because families receiving classroom messages in two apps stop reading both.
- Translation. Both translate. Paying for two translation pipelines is pure duplication, and the two will produce different renderings of the same phrase, which families notice.
- The family mobile app. Two apps means two install prompts, two sets of notification settings and two support burdens for your front office. This is the most expensive duplication and it is measured in staff time rather than licence fees.
- Announcements. Classroom announcements in the portfolio tool and district announcements in the comms platform is workable. Both doing both is how a closure notice gets missed.
A workable rule: anything about a specific child's learning goes in the portfolio tool. Anything the district would need to produce under a records request goes in the communications platform. Announcements follow whoever is sending — teacher to their own class, district to everyone.
Elementary against secondary
Portfolio tools skew hard to K–5 and there is a structural reason. In elementary school, one teacher owns one group of students all day, there is physical work worth photographing, and families want to see it. By middle school a student has six teachers, the work is increasingly digital and submitted through a learning management system, and the portfolio model stops matching the timetable.
District notification requirements do not vary this way at all. A closure notice, an attendance notice and an emergency message have identical requirements in kindergarten and in twelfth grade. That asymmetry is the practical argument for two products in an elementary-heavy district: the portfolio tool earns its money in K–5 and the communications platform earns its money everywhere.
It also affects how you should read pricing. A per-student portfolio licence across a whole district pays for capability that secondary teachers will not use. Ask whether the vendor licenses by school or by band, because in a K–12 district that difference is larger than any negotiation.
What we can substantiate on our side of the boundary
Since we are conceding the entire media and portfolio category, it is worth being precise about what the other half actually consists of, and all of it is checkable rather than adjectival.
Isolation is enforced by Postgres row-level security running under a non-owner, DML-only database role inside every transaction, so table ownership cannot silently bypass it. With no organisation context set, policies evaluate against NULL and return zero rows — it fails closed rather than open. A cross-tenant leakage suite runs in CI against a real Postgres instance, including a regression check for owner bypass.
Every state-changing action is written to a per-organisation audit log where each entry's hash covers the previous hash and the canonical event, serialised under an advisory transaction lock so concurrency cannot corrupt the chain, and append-only at two independent layers: UPDATE and DELETE revoked at the role, and row-level security policies that permit only INSERT and SELECT.
Around that sits a 28-endpoint public REST API with keys hashed at rest and shown once, signed outbound webhooks with an HMAC over timestamp and body plus a DNS-resolving SSRF guard and automatic disable after repeated failures, and an MIT-licensed CLI and MCP server. None of it helps a teacher share a photograph, which is exactly the point of this page.
Do not buy us to replace Seesaw. If the thing your teachers value is student work going home, we will disappoint them in the first week and you will have spent your credibility on it. Buy us for the notices, keep them for the portfolios, and be clear with staff about which is which.
Questions people actually ask
Can Seesaw replace a district communication platform?
No. Seesaw has no district-wide notification capability, no voice channel, no tamper-evident audit trail and no cross-school role governance. It is a portfolio product with classroom messaging, and it is very good at that. Districts that lean on it as the channel of record discover the gap during a closure or a records request.
Does Kastr support photo and video sharing?
No, and not in a limited way — there is no upload path, no attachment storage and no media sharing anywhere in the product. If teachers need to send photographs, you need a product that does that, and it is not us.
Should an elementary-heavy district buy both Seesaw and a comms platform?
Often yes, with a clear boundary. Portfolio work about a specific child goes in Seesaw; anything the district would need to evidence later goes in the communications platform. The saving comes from deciding which product owns messaging, translation and the family app rather than paying for both twice.
How much does Seesaw cost a district?
Seesaw does not publish district pricing; it is quoted per school or per district by plan tier. Ask whether licensing is by band, since a K–12 per-student rate pays for capability secondary teachers will not use. For contrast, our rate is published: $3.50, $3.25 or $3.00 per student per year by enrolment band.
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.