Safe by design.
Proven by numbers.
Seven-layer defence on every message, two independent moderation engines, and a public block-log a parent can audit at any time.
Messages screened
Total blocks
Blocks · last 30 days
NeMo Guardrails blocks
The stack
Every message passes through 7 gates
What we block
9 harm categories, every message, every account.
Two independent moderation engines
We deliberately run two unrelated systems. If one misses something, the other catches it.
OpenAI omni-moderation + custom blocklist
MongoDB-managed keyword/phrase rules · OpenAI Moderation API
NVIDIA NeMo Guardrails
gpt-4o-mini · input rails: · output rails:
Auditable, retained, parent-accessible
Block evidence is the metadata (reason, category, timestamp, message excerpt). Teen conversation content auto-deletes after 90 days regardless.
Aligned with
Still got questions?
Read the plain-English parent guide, see our schools compliance pack, or talk to a human on our team.
Numbers refresh on every page load · as of —
HiBFF uses essential cookies only — to keep you logged in and remember your preferences. We do not use advertising or tracking cookies. Privacy Policy