AiDren vs LLM Guard
LLM Guard is an open-source Python library of input and output scanners that you host, configure and maintain yourself. AiDren is a hosted proxy: you change your base URL and get screening, response scanning and model-file scanning without running anything. Choose LLM Guard for full control and data that never leaves your infrastructure.
If you've got security engineers and want full control with no third party in the request path, LLM Guard is the honest choice — see where below. LLM Guard is a project of Protect AI, referenced here for identification and comparison only.
Side by side
| AiDrenThis siteHosted proxy | LLM GuardOpen-source, MIT licence | |
|---|---|---|
| What it protects | ||
| Prompt-injection & jailbreak blocking | ✓Yes | ✓Yes — 15 input scanners, if you enable and tune them |
| Output & data-leak scanning | ✓Yes, on by default | ✓Yes — 20 output scanners, if you configure them |
| Malicious model-file scanning | ✓Built in, six formats | –Not in LLM Guard — a separate library (ModelScan) |
| Agent egress / outbound-call monitoring | ✓Yes | –No — you'd build this yourself |
| Rule customisation | ~Term, regex, topic and threshold policy engine, per key | ✓Full source-level control — every scanner is yours to edit |
| Getting started | ||
| How you integrate | Change your base URL. One line. | pip install, then call scanners in your own code path |
| Time to first protection | ~5 minutes | Days — install, wire into every call, tune thresholds |
| Hosting | Managed — nothing to run | You host it, on your own infrastructure |
| Ongoing maintenance | ✓None | –Patching, model updates, tuning — ongoing |
| Commercial | ||
| Licence cost | £49 / £149 / £399 a month by tier | Free (MIT licence) |
| Real cost | Flat monthly fee, no engineering time | Free licence + engineering time to deploy, wire in and maintain |
| Team accounts & audit log | ✓Unlimited seats, every plan | –You build your own auth and logging |
| Best fit | ||
| Choose this if… | You want it running in minutes with nothing to host, patch or tune | You have security engineers, want zero third parties in the request path, and have time to run it properly |
✓ Covered / an advantage ~ Partial or varies – Not covered
The short version: LLM Guard is free and fully in your control, at the cost of hosting, wiring and maintaining it yourself, plus a separate tool for model-file scanning. AiDren is the same three jobs — injection, output, model files — plus egress monitoring, hosted, for a flat monthly fee.
Where LLM Guard is genuinely ahead
We'd rather you knew this than found out after signing up.
- Zero third party in the request path. Self-hosted means your prompts never leave your own infrastructure — the strongest possible answer to a "who sees our data" question.
- Full source-level control. Every scanner is a Python module you can read, fork and edit. AiDren's policy engine covers the common cases (term, regex, topic, threshold) but isn't source-level control.
- No recurring fee. MIT licence, free forever — the cost is entirely your own engineering time, not a subscription.
LLM Guard alternatives: how to choose
LLM Guard is a strong option, so the real question is whether you want to run it. Four things decide it.
- Control and data path. Self-hosting means prompts never leave your infrastructure. A hosted proxy sees your traffic in order to screen it, so check the privacy policy against your requirements.
- Engineering time. The licence is free, but you deploy it, wire it into every model call, tune the scanners and keep it patched. A hosted proxy trades that time for a monthly fee.
- Coverage. LLM Guard's repository lists 15 input scanners and 20 output scanners. Model-file scanning is a separate library, and egress monitoring is not part of it. AiDren covers injection, responses, model files and egress in one product, but does not ship an equivalent of every LLM Guard scanner.
- Customisation. With LLM Guard every scanner is source you can edit. AiDren's policy engine covers five rule types (term, regex, topic, limit and system-prompt leak) per key, which is less flexible.
Choose LLM Guard if you have security engineers, want no third party in the request path and have time to run it properly. Choose AiDren if you want protection running in minutes with nothing to host, patch or tune.
Switching from LLM Guard
You do not have to choose all at once. A low-risk way to move:
- Step 1. Leave your LLM Guard scanners running. Start a trial, add your upstream key and create a proxy key.
- Step 2. Change your SDK's base URL to
https://api.aidren.co.ukand use the proxy key. - Step 3. Put the key in monitor mode and compare what AiDren would block with what your scanners catch.
- Step 4. Retire the scanners AiDren replaces. Keep any LLM Guard scanner AiDren has no equivalent for, such as the Toxicity and Bias scanners in LLM Guard's list.
AiDren vs LLM Guard FAQ
Is AiDren an LLM Guard alternative?
If you want similar kinds of checks without hosting them, yes. LLM Guard is an open-source Python library you install, wire into your code and maintain. AiDren is hosted and you point your base URL at it. If you need no third party in the request path or source-level control of each scanner, LLM Guard is the better fit.
Is LLM Guard free?
Yes. It is released under the MIT licence. The cost is the engineering time to host, deploy, tune and patch it.
How many scanners does LLM Guard have?
Its repository lists 15 input scanners and 20 output scanners (last checked 1 October 2026). AiDren does not ship an equivalent of every one of them.
Can I use LLM Guard and AiDren together?
Yes. They are not mutually exclusive. You can keep LLM Guard in-process for scanners AiDren does not have and route traffic through AiDren for hosted injection screening, response scanning and model-file scanning.
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Sources, last checked 1 October 2026: LLM Guard repository (MIT licence, scanner counts).
This comparison reflects our reading of the public LLM Guard documentation as of September 2026. Features change often, so check the project directly before deciding. LLM Guard is a project of Protect AI, referenced here for identification and comparison only; this is not an LLM Guard or Protect AI publication. Think we've got something wrong? Tell us and we'll fix it: [email protected].