Spam Hexer vs Zero Spam AI Review vs GravityAgent: an honest comparison for Gravity Forms sites
Competitor details verified on 2026-09-04 against the sources listed at the end. If you find something out of date, tell us at [SUPPORT EMAIL] and we will fix it.
If you run Gravity Forms and you are tired of spam, you now have three plugins that use an AI model to read each submission and decide whether it is genuine. Two of them are free. We make the third one, and it is not free past 250 submissions a month. So let us start with the part a vendor comparison usually buries.
The asymmetry, up front
Gravity Wiz's Spam Hexer and GravityKit's Zero Spam AI Review are both free plugins, and both are good. They come from the two most trusted third-party developers in the Gravity Forms ecosystem, and both are Gravity Forms Certified Developers. Neither charges you for the plugin. Both run the AI step through a provider account you set up and pay for yourself, either an OpenRouter key or, on WordPress 7.0 and later, the Connectors screen in WordPress core.
GravityAgent is a hosted service. There is no key to paste and no provider account to open; you install the plugin, press Activate, and switch a form on. We run the model and pay for it, which is why the free tier has a limit and the paid tiers have prices.
That single difference explains almost everything else in the table below. If you are comfortable managing a provider key and a model bill, and you have one or two sites, the free plugins may be all you need. If you have nobody to do that, or you have to do it twenty-five times, keep reading.
Side by side
| Spam Hexer (Gravity Wiz) | Zero Spam AI Review (GravityKit) | GravityAgent | |
|---|---|---|---|
| Price | Free | Free plugin; AI usage billed to your own provider | Free for 250 scored submissions / month on 1 site; paid plans from $99 / year |
| Who pays for the model | You, through your provider account | You, through your provider account | We do |
| Setup | OpenRouter key, or WordPress 7.0 Connectors | WordPress 7.0 and Connectors | Install, Activate, switch a form on. No key. |
| Which submissions the AI reads | Every submission, as an optional layer over a browser proof-of-work check | Only entries already blocked by Zero Spam's token check | Every submission on a form you switch on |
| Per-entry confidence and reasoning | Yes: score, reason codes, AI cost | Yes: classification, confidence and a short reason as an entry note | Yes: verdict, spam likelihood, plain-language reasoning, and what informed the decision |
| Tell it about your business | Yes, custom context | Yes, global and per-form instructions | Yes, a notes field; plus a site profile built automatically from your public pages |
| Builds a profile of your site itself | No | No | Yes, from your public pages at activation and about every 60 days |
| Learns from your Spam / Not Spam corrections | No | No | Yes: your corrections inform that form's future decisions |
| Suppresses notifications, feeds and confirmations for spam | Yes, native spam status | Yes | Yes, native spam status |
| Behaviour when the AI is unavailable | See their documentation | See their documentation | Fail-open: the entry is admitted and flagged "Not scored" with the reason |
| Several sites on one licence | No multi-site view | No multi-site view | Growth: 5 sites; Agency: 25 sites, each learning from its own corrections |
| Where to get it | Gravity Forms add-on directory | Gravity Forms add-on directory and WordPress.org | WordPress.org (free build) and gravityagent.io |
| Gravity Forms Certified Developer | Yes | Yes | No |
A note on the fail-open row: we have not tested how the other two behave when their provider is down or the key has lapsed, so we say nothing about it. Ours is documented because it is the promise the product is built around.
What "learns from your corrections" means, and why the others do not do it
Every one of these plugins will get a call wrong sometimes. The question is what happens next.
With Spam Hexer and Zero Spam AI Review, you mark the entry Not Spam with Gravity Forms' own button, the entry is restored, and the next similar submission gets the same treatment as the last one. You can add a sentence to the custom instructions by hand, which works, but it is you doing the learning.
With GravityAgent, that same Not Spam click is the correction. The plugin records it and sends the relevant past corrections along as examples with that form's later submissions, so a correction informs future decisions from the very next entry. There is no training run and no model tuning; the model is shown what you decided last time. Your corrections stay in your WordPress database, read live from the entries they belong to. We keep the label you chose and a decision id, never the content, and if you delete the entry the example disappears with it.
This is the reason GravityAgent is a hosted service rather than a plugin with a key field. Selecting and sending the right examples per form, building a site profile from your public pages, and metering all of it needs a backend. That backend is what you are paying for on the paid tiers.
How careful is it?
We tuned GravityAgent precision-first, because a spam filter that eats a real enquiry costs more than one that misses a spam. On our benchmark of 220 reviewed submissions across six synthetic sites, it produced 0 false positives on 95 genuine submissions, with 87.2% recall on spam. That is a benchmark, not a promise about your site: it means the threshold is set so that when the model is unsure, the entry comes through.
Only a clean verdict can mark an entry spam. A timeout, an outage, a reached limit, an expired plan, a malformed response or a bug in our own code admits the entry and flags it "Not scored" with the reason on the entry itself. And anything another filter has already marked spam, including Gravity Forms' honeypot or Akismet, is left exactly as it is, with no call made.
We have no comparable numbers for the other two and will not invent them.
When to pick them
Pick Spam Hexer if you want a free, well-supported filter from a developer you probably already buy from, you are happy to hold an OpenRouter key or run WordPress 7.0 Connectors, and you like the browser proof-of-work layer in front of the AI.
Pick Zero Spam AI Review if you already run GravityKit's Zero Spam, you are on WordPress 7.0 with Connectors, and you want the AI to review only what the token check has already blocked, which keeps your model bill near zero.
Pick GravityAgent if nobody on your side wants to manage a provider key and a model bill; you run several client sites and want one licence, one click per site and no per-site configuration; you want the filter to take your corrections without you writing instructions; or you need a privacy posture you can forward to a client's IT contact unchanged: no submission content stored, nothing trained on your data, per-field exclusion, deletion that follows the entry.
Pick none of the above if your spam is entirely bot-shaped and a honeypot or a CAPTCHA already stops it. AI review earns its place when the spam reads like a person.
What GravityAgent costs
| Free | Starter | Growth | Agency | |
|---|---|---|---|---|
| Price | $0 | $99 / year | $249 / year | $599 / year |
| Sites | 1 | 1 | 5 | 25 |
| Scored submissions / month | 250 | 2,000 | 10,000 | 50,000 |
Every tier learns from corrections, builds the site profile and fails open. A 14-day Growth trial needs no card. If a month runs past its limit, scoring pauses after a small grace allowance and submissions come through unscored; we never charge for overage.
Install free from WordPress.org · Read how the learning loop works
Sources
Competitor facts were verified on 2026-09-04 from the developers' own pages:
- Gravity Wiz, Spam Hexer: https://gravitywiz.com/gravity-forms-spam-hexer/ ; https://gravitywiz.com/introducing-gravity-forms-spam-hexer/ ; https://gravitywiz.com/comparing-spam-solutions-for-gravity-forms/
- GravityKit, Zero Spam AI Review: https://www.gravitykit.com/docs/gravity-forms-zero-spam/ai-spam-review/
- WordPress 7.0 Connectors API: https://make.wordpress.org/core/2026/03/18/introducing-the-connectors-api-in-wordpress-7-0/
- Gravity Forms Certified Developers: https://www.gravityforms.com/certified-developers-and-add-ons/
- Gravity Forms' own anti-spam guide (no native AI filter): https://www.gravityforms.com/blog/gravity-forms-anti-spam-wordpress/
GravityAgent is not affiliated with Gravity Forms, Rocketgenius, Gravity Wiz or GravityKit. Product names belong to their owners.