Education · head to head
Securly vs Stellarium
Securly
Education
Web filtering, student safety monitoring and device management for K-12 schools
- From
- On request
- Rated
- -
Stellarium
Education
Free open source desktop planetarium software, distinct from the paid Stellarium Mobile Plus app
- From
- Free
- Rated
- -
The short version
- Only Stellarium has a free tier, so it costs nothing to try first.
- Each has a real cost: Securly pricing stacks by module and only Filter has rates that surface publicly, so the quoted total for Filter plus Aware plus On-Call is routinely several times the number a district budgeted from the filtering line alone.; Stellarium it is desktop-only software, so it has no native touch-optimised phone interface; the similarly named mobile app is a different paid product from a different company.
- They diverge on capability: Securly covers Filter, Stellarium covers Photorealistic sky rendering.
- Prices and features above were last checked on 1 September 2026.
Where they differ
Only the attributes on which Securly and Stellarium actually diverge.
| Attribute | Securly | Stellarium |
|---|---|---|
| Starting price | On request | Free |
| Pricing model | Per student per year by module | Open source, no licence fee |
| Free tier | No | Yes |
| Platforms | Web, iOS, Android, Chrome OS, Windows | Windows, macOS, Linux |
Identical on both: user rating (Not yet rated), category (Education).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in Securly
- Filter
- Aware
- On-Call
- Classroom
- MDM
- Pass
- Home
- Delegated admin
Only in Stellarium
- Photorealistic sky rendering
- Large object catalogue
- Telescope control
- Scripting engine
- Free and open source
- Plugin ecosystem
What people use each for
The jobs each tool is most often brought in to do.
Securly
- A district that must show CIPA compliance for take-home Chromebooks used on home broadband, where network-level filtering does nothingnot Stellarium
- A district whose safeguarding policy requires that a human being reads a self-harm alert within minutes at any hour, including school holidaysnot Stellarium
- A one-to-one iPad programme needing Apple device enrolment, filtering and classroom control from a single agent rather than threenot Stellarium
- A district under pressure from parents who want visibility of what their child does on the school device at home, without the school having to field each request by handnot Stellarium
Stellarium
- A student or educator wanting a serious, scriptable planetarium tool without a budget line itemnot Securly
- An amateur astronomer wanting telescope control from desktop software they can inspect and modifynot Securly
- Someone running a planetarium display or public astronomy event on a scripted shownot Securly
- A hobbyist who wants a large object catalogue without paying a subscription, and does not need a phone appnot Securly
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Securly
- Pricing stacks by module and only Filter has rates that surface publicly, so the quoted total for Filter plus Aware plus On-Call is routinely several times the number a district budgeted from the filtering line alone.
- The safety scanning generates false positives at volume, including song lyrics, creative writing and health-class assignments, and each one consumes counsellor or administrator time that the vendor does not pay for.
- Alerting on student writing is a surveillance decision with real community consequences, and districts that deploy it without an explicit board policy and parent notification have faced local objections after the fact.
- Coverage is strongest on managed Chromebooks; personal devices, non-Chrome browsers and encrypted apps outside the agent leave gaps that the compliance story quietly depends on nobody testing.
- Per-student pricing is charged on enrolment rather than on devices, so a district that issues devices to only some year groups still pays for every student on the roll.
Stellarium
- It is desktop-only software, so it has no native touch-optimised phone interface; the similarly named mobile app is a different paid product from a different company.
- As a volunteer-maintained open source project, support is community-based rather than a guaranteed commercial help desk.
- The interface, while capable, is less immediately intuitive for a first-time user than a polished commercial phone app.
- Telescope control and some advanced plugins require additional setup that a non-technical user may find fiddly.
- Because it shares a name with the unrelated paid Stellarium Mobile Plus app, buyers researching pricing online can easily conflate the two products.
Pricing, plan by plan
Securly
On request- Filter$undefined/year
- Web filtering on and off network
- Tiered per-student rates that fall as enrolment rises
- Published in some purchasing co-operative catalogues, not on the vendor site
- Aware$undefined/year
- Automated scanning of email, documents and search for safety risk
- Quoted per student, no public rate
- On-Call$undefined/year
- 24/7 human review and escalation of serious alerts
- Quoted per student, priced on top of Aware
- Classroom, MDM and Pass$undefined/year
- Sold as separate per-student modules
- Quoted
Stellarium
Free- Stellarium DesktopFree
- Full software, GPL licensed
- No account, ads or subscription
- Community-developed plugins
Which should you pick?
Choose Securly if
- You need filter.
- You work on Web, iOS, Android, Chrome OS, Windows.
- You also want aware.
Choose Stellarium if
- You need photorealistic sky rendering.
- You want to start without paying.
- You work on Windows, macOS, Linux.
- You also want large object catalogue.
Questions people ask
- Is Securly or Stellarium better?
- Neither clearly leads. Securly starts at On request and Stellarium at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Securly or Stellarium?
- Stellarium has a free tier; the other does not. Paid plans start at On request for Securly and Free for Stellarium.
- Does Securly or Stellarium run on more platforms?
- Securly runs on Web, iOS, Android, Chrome OS, Windows. Stellarium runs on Windows, macOS, Linux.
- Can I use Stellarium for free?
- Yes. Stellarium has a free tier, so you can try it without paying. Securly starts at On request.
- What is Securly best used for?
- Securly is most often used for a district that must show cipa compliance for take-home chromebooks used on home broadband, where network-level filtering does nothing, a district whose safeguarding policy requires that a human being reads a self-harm alert within minutes at any hour, including school holidays, a one-to-one ipad programme needing apple device enrolment, filtering and classroom control from a single agent rather than three, a district under pressure from parents who want visibility of what their child does on the school device at home, without the school having to field each request by hand. Of those, a district that must show cipa compliance for take-home chromebooks used on home broadband, where network-level filtering does nothing and a district whose safeguarding policy requires that a human being reads a self-harm alert within minutes at any hour, including school holidays are not what Stellarium is typically brought in for.
- What can Securly do that Stellarium cannot?
- Securly covers Filter, Aware, On-Call, Classroom. Stellarium covers Photorealistic sky rendering, Large object catalogue, Telescope control, Scripting engine.
Answered from the vendors’ own pages
Securly: Does Securly publish pricing?
Not on its own site. Tiered per-student rates for Filter appear in some US purchasing co-operative catalogues, falling as enrolment rises, but Aware, On-Call, Classroom, MDM and Pass are quoted.
Stellarium: Is Stellarium really free?
The desktop software is free and open source under the GPL licence. The separate mobile app, Stellarium Mobile Plus, is a different paid product.
Securly: What is the difference between Aware and On-Call?
Aware is the automated detection that produces alerts. On-Call is the staffed service that reads the serious ones out of hours and phones your escalation contacts. Buying Aware alone leaves the triage with your own staff.
Stellarium: Is the mobile app made by the same team?
No. Stellarium Mobile Plus is built by Noctua Software, a different company, and is sold on subscription.
Securly: Does it filter on home internet?
Yes, filtering follows the managed device rather than the network, which is the point for take-home Chromebook programmes.
Stellarium: What platforms does the free version run on?
Windows, macOS and Linux desktop.
Securly: Is student data used for anything else?
Securly signs the US Student Privacy Pledge and district data processing agreements; check the specific DPA rather than the marketing page, since scanning scope and retention are negotiated terms.
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