GoPhish is the best free phishing simulation tool in 2026 — a full open-source campaign engine you can run at zero licence cost — with KnowBe4's free Attack Simulation Test, Trend Micro's Phish Insight and King Phisher covering the other three genuinely free routes. Every option here costs nothing to start; what separates them is how much infrastructure and admin time you trade away to keep the price at zero.
Key takeaways
- GoPhish is the most capable free tool: open source (MIT licence), self-hosted, with a template editor, campaign scheduling, click tracking and a REST API.
- KnowBe4's free Attack Simulation Test sends a single simulated phishing email across your whole workforce and reports the vulnerability rate — a one-off benchmark, not an ongoing programme.
- Trend Micro Phish Insight is a free hosted simulation service for IT administrators — no infrastructure to run, but limited templates and no training content.
- King Phisher is a second open-source toolkit (BSD 3-clause licence) with a desktop client, web-page cloning and credential-harvesting landing pages — powerful, and entirely your responsibility.
- Free tools test; they do not train. The moment you need auto-enrolled remediation courses and audit-ready reporting, that is the paid tier's job.
What a free phishing simulation can and cannot do
A free tool answers one question cheaply: if a phishing email landed in your staff's inboxes today, who would click? That benchmark is worth running — the Australian Signals Directorate's Essential Eight treats user awareness as baseline hygiene, and a click rate is the clearest evidence of where you stand.
What free tools generally do not include: the training loop after the click, a maintained template library matched to the scams your region actually sees, and reporting formatted for an auditor, insurer or client. Budget admin time for all three if you stay free.
Free phishing simulation tools at a glance
| Tool | Type | Best for | Main limitation |
|---|---|---|---|
| GoPhish | Open source, self-hosted (MIT) | Technical teams wanting full control | You run the server, domains and SMTP; no training content |
| KnowBe4 Attack Simulation Test | Free vendor test | A one-off workforce benchmark | One test email, not an ongoing programme |
| Trend Micro Phish Insight | Free hosted service | IT admins who want zero infrastructure | Limited templates; standard level only |
| King Phisher | Open source, self-hosted (BSD 3-clause) | Penetration testers and red teams | Desktop client/server setup; no training content |
1. GoPhish: the best free phishing simulation tool
GoPhish is the open-source phishing toolkit. You download a binary for Windows, macOS or Linux, run it, and get a web UI with a full HTML template editor, sending profiles, landing pages, campaign scheduling and near-real-time tracking of email opens, clicks and submissions. A REST API and Python client make it scriptable, and it is released under the MIT licence with an active community maintaining it and hardened forks.
- Pros: genuinely free with no seat limits; full control over templates and infrastructure; REST API for automation
- Cons: you provide and maintain the SMTP relay, sending domains and hosting; no training content, auto-remediation or compliance reporting
- Verdict: the default choice if you have someone technical to run it. Buy (it is free) for technical teams; Skip for everyone else.
2. KnowBe4 free Attack Simulation Test: best one-off benchmark
KnowBe4's free test sends one simulated phishing email to each user in your organisation and reports back how many clicked, quantifying your workforce's vulnerability. Its dedicated sandbox covers email phishing, reply phishing, social media phishing and QR-code phishing, with a target list you upload once. It is the fastest way to get a defensible number in front of a board — but it is a single measurement, not a monthly programme.
- Pros: zero setup infrastructure; vendor-run; immediate vulnerability report; covers modern vectors like QR phishing
- Cons: a one-off test rather than an ongoing cadence; no training content included; vendor upsell follows
- Verdict: Buy for the free benchmark; move on to a real programme afterwards.
3. Trend Micro Phish Insight: best free hosted service
Phish Insight is Trend Micro's free phishing simulation service aimed at IT administrators. You sign up with your details, verify your email, and get access to the standard (free) level — hosted campaigns and reporting with no server to maintain. For a small team that wants simulations without owning infrastructure, it removes exactly the burden that makes GoPhish hard.
- Pros: free, fully hosted, no infrastructure to run; vendor-maintained templates and reports
- Cons: standard level only — advanced features sit in the paid TrendAI Vision One security-awareness tier; smaller template library than paid platforms
- Verdict: Buy for small teams wanting zero-maintenance simulations.
4. King Phisher: best for penetration testers
King Phisher is an open-source phishing campaign toolkit released under the BSD 3-clause licence. Its desktop client and server architecture give full control over emails and server content: campaigns with embedded images and calendar invitations, web-page cloning, credential-harvesting landing pages, SPF checks, visitor geo-location and SMS alerts on campaign activity. It is built for security professionals running deliberate, complex scenarios — not for an office admin scheduling a monthly test.
- Pros: free and open source; fine-grained control of emails and landing pages; scenario features (SMS alerts, calendar invites, page cloning)
- Cons: client/server setup with real operational overhead; no training content; needs a security professional to run safely
- Verdict: Buy for pentest teams; Skip for awareness programmes.
When free is the wrong answer
A free tool tells you who clicked. It does not teach them. If you need every click followed by a short remediation course, a report an auditor will accept, or — for MSPs — delivery under your own brand across many clients, the free tier cannot close the loop. Paid platforms such as Cyber Aware automate the whole cycle: phishing simulations that auto-enrol anyone who clicks into training, a per-learner Human Risk Score, and gap assessment evidence mapped to the Essential Eight.
A practical pattern: run a free benchmark once to get your baseline, then put the ongoing cadence on a platform that handles the training side automatically.
FAQ
What is the best free phishing simulation tool in 2026? GoPhish — an open-source, self-hosted toolkit with a template editor, campaign tracking and a REST API. It is the most capable free option for teams that can run their own infrastructure.
Is GoPhish really free? Yes — it is released under the MIT licence with no seat limits. Your costs are the infrastructure: a server, sending domains and an SMTP relay.
Can I run a phishing test for free without any setup? Yes — KnowBe4's free Attack Simulation Test and Trend Micro Phish Insight are hosted: sign up, upload or import your target list, and run. Both trade control for convenience.
Do free phishing tools include training? No — none of the four free options above includes training content or auto-remediation. Training loops are the main reason teams move to a paid platform.
What does Cyber Aware cost compared to free tools? Cyber Aware quotes per-seat pricing with no seat minimums — there is no free tier, but simulations, auto-enrolled training and Essential Eight-mapped evidence all run from one setup.
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One last thing
Free gets you a number; paid gets you behaviour change. Whichever free tool you run, treat the first campaign as a baseline — and make sure something happens the day someone clicks, because the click rate only falls when the lesson follows the click.