Is Harmonic or Zscaler better for AI endpoint control?

Neither is scored on this site. Harmonic describes 2 of four product control types and Zscaler 1 on the pages we read, and they differ on 10 recorded facts. Which fits depends on the AI tools people use, your devices, where the work happens and whether you block or guide; the finder checks those.

Which of the two decides on a tool call before it runs?

Harmonic: Partly. Zscaler: Not in our sources. Warn or ask: Harmonic Matches, Zscaler Not in our sources.

Do Harmonic or Zscaler publish prices?

Harmonic: Three named tiers (Explore, Guide, Command) with no prices; a full prompt audit log is an add-on on Guide and Command. Zscaler: Not published (demo request).

HEAD-TO-HEAD · FACTS ONLY

Harmonic vs Zscaler: AI endpoint control facts side by side

Short answer

Harmonic describes 2 of the four product control types on the pages we read and Zscaler describes 1; they differ on on-device control, browser extension, network or SSE proxy and AI or MCP gateway. On decisions, Harmonic describes some control over tool calls and Zscaler does not describe tool-call decisions on the pages we read. We do not score either; the right choice depends on the AI tools people use, your devices, your current stack and whether you block or guide.

By The Device Desk · Endpoint AI Finder · Published 2026-10-11

Desk research from public vendor pages read on 27 September and 11 October 2026. Profiles follow our published method; we did not run the products.

Vendor pages read September and October 2026 · updated 2026-10-13

Where do their controls sit?

Filled or hatched marker: Harmonic
Dashed teal ring: Zscaler, described

DEV Filled marker: described on the product pages we read
DEV Hatched marker: partly described (another component, a narrower scope, or method not detailed)
DEV Dashed marker: not in our sources (it may exist; we did not find it)

The map shows where each product's own pages describe a control, or where your answers point. It is not a measure of how well a product works.

What are the facts, side by side?

Harmonic Security and Zscaler Generative AI Security, from each product's own pages. Differs is computed from recorded statuses, not wording.
Fact	Harmonic	Zscaler
Owner	None	None
Positioning	A data protection product for everyday AI use, sold as Explore, Guide and Command, covering browser extensions, desktop apps and CLI tools, MCP gateways and an API.	Zscaler's controls for employee use of generative AI: prompt-level visibility, allow or block by app, DLP blocking across GenAI apps, browser isolation that disables cut, paste and download, and data security for Microsoft Copilot.
How it reaches devices	Rolls out through Intune, JAMF, Kandji or Group Policy. Source: Harmonic Security homepage · Read 27 Sep 2026	Delivered with Zscaler's cloud security service in the network path; endpoint agents are not described on the page we read. Source: Zscaler: Secure the use of generative AI · Read 11 Oct 2026
On-device controlDiffers	Partly describedDeployment options include desktop apps and AI agents, rolled out through device management; the on-device component is not described in detail. Source: Harmonic Security pricing (re-read) · Read 11 Oct 2026	Not in our sourcesNot described on the pages we read.
Browser extensionDiffers	DescribedBrowser extensions are a listed surface, with block, warn or log actions. Source: Harmonic Security homepage · Read 27 Sep 2026	Not in our sourcesNot described on the pages we read.
Network or SSE proxyDiffers	Not in our sourcesNot described on the pages we read.	DescribedSee all input prompts users send to apps, allow or block apps, block sensitive data with DLP across GenAI, and isolate the browser to disable cut, paste and download. Source: Zscaler: Secure the use of generative AI · Read 11 Oct 2026
AI or MCP gatewayDiffers	DescribedMCP gateways are a listed surface, and Harmonic Command governs at the MCP layer and at the tool surface. Source: Harmonic Security: Command · Read 27 Sep 2026	Not in our sourcesNot described on the pages we read.
Names the coding agents it coversDiffers	MatchesThe Guide tier adds desktop AI apps and developer tools, naming Claude Code, GitHub Copilot, ChatGPT Desktop and Microsoft 365 Copilot. Source: Harmonic Security pricing (re-read) · Read 11 Oct 2026	Not in our sources
Decides on a tool call before it runsDiffers	PartlyThe Command tier adds MCP client and server discovery, agent permissions for read, write and execute, and MCP server tool controls. Source: Harmonic Security pricing (re-read) · Read 11 Oct 2026	Not in our sources
Controls what goes into browser AI	MatchesBlock, warn or log on AI use in the browser. Source: Harmonic Security homepage · Read 27 Sep 2026	MatchesPrompt-level visibility, DLP blocking across GenAI apps, and browser isolation that disables cut, paste and download. Source: Zscaler: Secure the use of generative AI · Read 11 Oct 2026
Rolls out through EDR or device management you runDiffers	MatchesRolls out through Intune, JAMF, Kandji or Group Policy. Source: Harmonic Security homepage · Read 27 Sep 2026	Not in our sources
Can warn or ask instead of only blockingDiffers	MatchesWarn is one of three actions, with block and log. Source: Harmonic Security homepage · Read 27 Sep 2026	Not in our sources
Can block an agent, tool or action	MatchesBlock is one of three actions. Source: Harmonic Security homepage · Read 27 Sep 2026	MatchesAllow or block GenAI apps, and block sensitive data with DLP. Source: Zscaler: Secure the use of generative AI · Read 11 Oct 2026
Has a watch-only or simulation modeDiffers	MatchesLog is one of three actions, for watching before enforcing. Source: Harmonic Security homepage · Read 27 Sep 2026	Not in our sources
Records who or what took each action	Not in our sources	Not in our sources
Also covers SaaS, cloud or homegrown AI	PartlyAn API is listed alongside device surfaces; SaaS or cloud agents are not described. Source: Harmonic Security homepage · Read 27 Sep 2026	PartlyData security for Microsoft Copilot, including misconfigurations. Source: Zscaler: Secure the use of generative AI · Read 11 Oct 2026
Has a public price or tiers (vendor site or marketplace)Differs	PartlyNames three tiers (Explore, Guide, Command) on its pricing page, without prices. Source: Harmonic Security: pricing · Read 27 Sep 2026	Not in our sources
Built into	None	None
Works with	None in our sources	None in our sources
Price	Three named tiers (Explore, Guide, Command) with no prices; a full prompt audit log is an add-on on Guide and Command. Source: Harmonic Security pricing (re-read) · Read 11 Oct 2026	Not published (demo request). Source: Zscaler: Secure the use of generative AI · Read 11 Oct 2026

Where do they differ?

On-device control: Harmonic partly describes it; Zscaler is not in our sources.
Browser extension: Harmonic describes it; Zscaler is not in our sources.
Network or SSE proxy: Harmonic is not in our sources; Zscaler describes it.
AI or MCP gateway: Harmonic describes it; Zscaler is not in our sources.
Names the coding agents it covers: Harmonic matches; Zscaler is not in our sources.
Decides on a tool call before it runs: Harmonic partly matches; Zscaler is not in our sources.
Rolls out through EDR or device management you run: Harmonic matches; Zscaler is not in our sources.
Can warn or ask instead of only blocking: Harmonic matches; Zscaler is not in our sources.
Has a watch-only or simulation mode: Harmonic matches; Zscaler is not in our sources.
Has a public price or tiers (vendor site or marketplace): Harmonic partly matches; Zscaler is not in our sources.

Choose Harmonic if

Your main risk is employees pasting sensitive data into AI tools and you would rather coach than block
You manage devices with Intune, JAMF, Kandji or Group Policy

Choose Zscaler if

You already route traffic through Zscaler and want GenAI controls there
Your main risk is sensitive data pasted or uploaded into GenAI web apps

Which limits should you check?

Harmonic

Tier names only, no prices, and the full prompt audit log is an add-on.
An activity record that separates a person from an agent is not described, and prompt injection protection is listed as coming soon.

Zscaler

Coding agents, MCP servers and local agent actions are not described on the page we read.
Warn or ask responses are not described, and no pricing is published.

Line up Harmonic and Zscaler with others Run the finder