Harmonic Security alternative: when you need masking and a gateway

A claims handler pastes a customer's letter into ChatGPT and asks for a summary. A guardrail fires within a fraction of a second and explains that the letter contains a national ID. That's a good moment of coaching. What happens next is the question this page is about: does she edit the text by hand, drop the task, or does the prompt go through with the ID swapped for a token and come back whole?

Maskflare wrote this page. Harmonic is a capable product and one of the closest alternatives to Maskflare for employee AI use, so we've kept to what it publishes and we say so where we couldn't find an answer.

What is Harmonic Security?

Harmonic Security sells AI usage control and data protection for employees. Its GenAI DLP page describes a full inventory of AI in use and inline guardrails that coach, warn or block in under 200 milliseconds, using purpose-built small language models that read the whole prompt or file. Its governance page adds override-with-reason warnings and configurable retention.

One detail matters for a fair comparison. The product pages we read talk about coaching, warning and blocking, but Harmonic's own llms.txt lists policy actions as allow, warn, redact and block. So it would be wrong to call Harmonic block-only. What we couldn't find is documentation of how redaction works, or of tokens that restore the original values in the model's answer.

It deploys as a browser extension and on desktops, and its llms.txt describes an MCP Gateway that adds policy enforcement and audit visibility for agent traffic. Its trust center lists ISO/IEC 27001:2022, SOC 2 Type 2 and ISO/IEC 42001:2023.

Who should choose Harmonic Security?

• Your first question is what people are doing with AI. Discovery and usage analytics are at the center of the product, with a full inventory from day one.
• You want coaching to be the main control. In-the-moment guidance and warnings with a reason to override are what it leads with.
• You need finished certifications now. Harmonic lists completed ISO 27001 and SOC 2 Type 2, plus ISO 42001. Maskflare's audits are still in progress.
• Your concern is employees, not your own apps. If you don't ship AI features, an API gateway adds nothing for you.
• You want broad app coverage first. Harmonic quotes more than 1,000 AI apps with prompt-level controls. Maskflare covers 7 AI web apps in depth.

Who should choose Maskflare?

1. People need to finish the task. Maskflare replaces values with reversible tokens and restores them where the answer repeats them, so a letter comes back complete and the provider never saw the data.
2. You also build with AI. The gateway covers your own apps: change one base URL, and the same rules that protect employees apply to OpenAI, Anthropic, Google Gemini, Mistral, xAI, DeepSeek, Groq, Together AI and Ollama. We couldn't find an equivalent LLM API gateway in Harmonic's public docs; its gateway is documented for MCP.
3. You handle European identifiers. 47 country packs validate national IDs by checksum, across all 27 EU member states, the United States, the United Kingdom, Switzerland, Norway, Iceland, Liechtenstein, Canada, Mexico, Brazil, Australia, New Zealand, Japan, South Korea, China, India, Singapore, South Africa, Türkiye, Albania and Kosovo. You can read exactly which detectors exist, and every match is explained.
4. You want to read the rules. Detection is deterministic patterns, checksums and context, plus a local named-entity layer for names, places and free-text details; every match is explained. An auditor can see why a value was or wasn't masked.
5. You'd rather no copy of a prompt existed. Maskflare never logs or stores prompts or responses. It records metadata, and keeps encrypted originals for 30 days only to restore answers.

Harmonic Security vs Maskflare, feature by feature

Can you run them together?

Yes, in principle, and it can make sense while you decide. Harmonic gives you usage visibility across a long list of apps; Maskflare handles the values in the apps and API traffic where people need to keep working. Two tools inspecting the same browser traffic can interfere, so test the pair in a small pilot. We haven't published a tested integration with Harmonic.

How do you move from Harmonic to Maskflare?

1. Keep your AI inventory. Export your list of AI apps in use and compare it with the 7 web apps Maskflare covers: ChatGPT, Claude, Gemini, DeepSeek, Perplexity, Mistral Le Chat and Microsoft 365 Copilot. Apps outside that list need another control.
2. Translate policies by outcome. Harmonic policies are written around data types, apps and roles. List what each should now do: mask, warn with justification, or block. Credentials are blocked in the browser by default.
3. Port custom keywords. Harmonic documents custom keyword detections. In Maskflare these become dictionaries or custom regex, and known customers can use Exact Data Match.
4. Pilot on ten laptops in alert mode. Deploy the desktop agent with Intune, Jamf or Group Policy, watch for a week, then switch rules to mask.
5. Add your own apps. Point one internal app at the gateway and compare it against your current traffic.

What Maskflare doesn't do

• It covers 7 AI web apps deeply, not hundreds. Discovery sees more apps than masking can protect.
• AI app discovery and coaching dialogs need the desktop agent on managed devices; personal phones and unmanaged laptops are out of reach.
• Prompt-injection detection runs on MCP tool results and tool listings, not on chat prompts, and there's no topic filtering.
• SOC 2 Type II and ISO 27001 audits are in progress. If you need a finished report today, factor that in.

Sources and how we checked

Based on public information as of November 3, 2026. Maskflare wrote this page, and vendors change their products, so check anything that matters with the vendor. “Not publicly documented” means we couldn't find it, not that the product lacks it. If something here is wrong, tell us and we'll correct it.

• harmonic.security/solutions/dlp-for-genai
• harmonic.security/solutions/ai-usage-governance
• harmonic.security/llms.txt
• trust.harmonic.security
• harmonic.security/resources/harmonic-product-update-september-2025