F5 Client-Side Defense alternatives for the payment page (2026)
By Laís Peixoto
Growth Marketer, Proteside
Published
Teams looking past F5 Client-Side Defense find other CDN and WAF modules (Cloudflare Client-Side Security, formerly Page Shield, and Akamai Client-Side Protection & Compliance), in-page agents (Feroot, c/side), an external monitor (Reflectiz) and Proteside's approach, which verifies the payment itself. The choice starts with where your application runs and what your checkout accepts.
Why teams evaluate other options
The checkout takes more than cards
A UPI or PayNow QR code, a Pix key, a Brazilian bank slip line or a USDT address never passes through a form. The attack swaps the recipient on screen, so the tool has to verify that data.
Blocking without a list to maintain
When mitigation depends on domain lists your team defines and rejecting a script is informational, operators want a block that happens in every session, before confirmation.
The application is not on F5
Stores on another CDN or without an F5 load balancer can insert the script by hand, but management stays in the Distributed Cloud console. Many teams prefer a tool that enters any platform with one line of code.
The short list
| Option | How it works | Makes sense for | Comparison |
|---|---|---|---|
| Proteside | A script on the payment page checks every QR code, payment key, bank slip line, wallet address and card field against what your server issued, and blocks the swap before confirmation. | Merchants paid through instant rails such as UPI, PromptPay, PayNow or Pix, by card, by bank slip or in stablecoins, who need protection and PCI DSS evidence from a single install. | F5 Client-Side Defense vs Proteside |
| Cloudflare Client-Side Security (antes Page Shield) | From the proxy, Cloudflare adds a report-only CSP header to a sample of pages and builds the inventory from browser reports; blocking happens through allow rules in the advanced tier. | Sites already behind Cloudflare that want script monitoring with nothing to install. | Cloudflare Page Shield vs Proteside |
| Akamai Client-Side Protection & Compliance (antes Page Integrity Manager) | Akamai's edge injects a detection script at the top of the page (or it is placed at the origin), analyzes script behavior and lets you restrict a malicious script with one click in the console. | Large operations on Akamai that want network threat intelligence and script inventory managed in the same console. | Akamai Client-Side Protection vs Proteside |
| Feroot PaymentGuard e DXSecure | Inventories the scripts on payment pages, records justifications and integrity, and alerts on changes to content and headers; runtime policy enforcement is described as optional. | Card-centric operations that need script governance across websites and mobile apps, with a report for the assessor. | Feroot vs Proteside |
| c/side Script Security | A snippet on the page watches third-party scripts in real sessions, keeps a history of what each script loaded and blocks by combining CSP with its own rules, with no reverse proxy and no DNS change. | Teams that want detailed visibility into the behavior of every third-party script, with compliance dashboards and alerts in chat tools. | c/side vs Proteside |
| Reflectiz PCI Module | An automated browser visits payment pages from outside, on a schedule, with no code on the site; blocking, when triggered in the interface, injects a CSP policy that excludes a domain. | Teams that cannot or prefer not to place a script on the page and accept detection with human review. | Reflectiz vs Proteside |
Choose the category before the vendor
CDN and WAF modules, such as those from F5, Cloudflare and Akamai, suit teams that already route the application through that platform: the script inventory shows up in the console they use every day. In-page agents, such as Feroot and c/side, enter with a script and watch every shopper on any infrastructure. External monitors, such as Reflectiz, visit the page from outside with no code on the site, which is why they do not follow each session.
All three families look at scripts and form fields, the ground of web skimming, where a script copies card data from the form. By what the public documentation describes, none verifies whether the QR code, account details or wallet address on screen are the ones the merchant issued. That verification is Proteside's category, and it includes the script inventory and the evidence for requirements 6.4.3 and 11.6.1 in the same installation.
The options in detail
Proteside
Proteside records what is legitimate on each payment page (the details of each charge, the form fields, the authorized scripts) and continuously verifies, in the payer's browser, what is displayed, what is copied and where the data goes. When it detects a mismatch, it stops the action before the payment is confirmed and logs the attempt.
The script inventory and the change history form the evidence for PCI DSS requirements 6.4.3 and 11.6.1. Installation is one line of code on any e-commerce platform, or a single integration for platforms and payment providers, with a dashboard, API and alerts.
Proteside is the right choice when: Choose Proteside when your checkout is paid through instant rails, bank slips or stablecoins as well as cards, when you need the payee swap blocked in real sessions, or when you want protection and PCI DSS evidence without changing your CDN.
Cloudflare Client-Side Security (antes Page Shield)
The feature, called Page Shield until March 2026 and now Client-Side Security, is available for domains proxied through Cloudflare. Documentation describes monitoring of scripts, connections and cookies, detection of malicious scripts and code changes, and content security rules that can block anything outside the allow list.
The documentation itself explains the mechanism: the report-only header goes out on a sample of responses, so a new script can take time to appear. Requirements 6.4.3 and 11.6.1 are covered in the advanced tier. Pix, boleto (Brazilian bank slip) and instant payment rails do not appear in the material.
Cloudflare Page Shield is the right choice when: your site is already behind Cloudflare, cards are the main payment method and sampled script monitoring satisfies your assessor.
Akamai Client-Side Protection & Compliance (antes Page Integrity Manager)
Client-Side Protection & Compliance (formerly Page Integrity Manager) inventories scripts, applies justifications and rules, monitors headers for requirement 11.6.1 and alerts on unauthorized scripts, payment data exfiltration and tampering. Public documentation says detections work for any site, wherever it is hosted, with configuration in the Akamai console.
Script injection can be set to a percentage of page views, and mitigation is described as a restriction applied with one click. For full coverage, injection has to run on every page view. The material covers scripts and card data; it does not address QR codes, payment keys or bank slip lines.
Akamai Client-Side Protection is the right choice when: your operation already runs on Akamai, your security team operates the console and human-approved mitigation fits your process.
Feroot PaymentGuard e DXSecure
Feroot centers its offer on compliance: PaymentGuard covers requirements 6.4.3 and 11.6.1 with script inventory, justifications, integrity checks and an evidence report for the QSA. Public documentation cites integrations with alerting and operations tools, and coverage of iOS and Android apps alongside websites.
The point to watch for anyone paid outside cards is scope: the public material speaks of scripts and card data, with no mention of QR codes, payment keys, boleto (Brazilian bank slip) or crypto wallets. For those payment methods, a payee swap sits outside what the tool describes checking.
Feroot is the right choice when: your priority is script governance and PCI DSS evidence across websites and mobile apps, and your checkout is paid mostly by card.
c/side Script Security
c/side defines itself as a client-side security platform. Public material describes an inventory with the content history of each script, a vendor graph, alerts, dashboards for requirements 6.4.3 and 11.6.1 and an endpoint for receiving CSP reports.
Its public page on crypto cites the swap of a wallet address copied to the clipboard, which brings it close to the problem Proteside solves. Pix, boleto (Brazilian bank slip) and the QR codes of instant payment rails such as UPI or PromptPay do not appear in the public documentation we consulted.
c/side is the right choice when: you want the detail of each third-party script's behavior and a crypto address swap is already your main concern outside cards.
Reflectiz PCI Module
Reflectiz describes its own approach as agentless: a sandboxed browser simulates the user journey, inventories scripts (including inside iframes), monitors headers for requirement 11.6.1 and exports evidence for the QSA. The platform also covers privacy and offensive testing.
The vendor's own material explains blocking as a script that stays inactive on the page until triggered in the interface, when it starts excluding a domain through CSP. It is a design choice: detection first, human intervention second. Scams that appear only to one specific buyer are not observed by simulated visits.
Reflectiz is the right choice when: your internal policy forbids adding scripts to the payment page and your security team reviews alerts before acting.
How to evaluate an alternative
- 1Where does the application run? A CDN or WAF module covers what passes through the vendor's platform; outside it, check whether manual insertion keeps the same functions and where management sits.
- 2Who blocks? A domain list your team maintains, a one-click approval, or automatic blocking in every session?
- 3What payment details does the page display? If there is an instant payment QR code, a Pix key, a bank slip line or a wallet address, the tool has to compare that data with what was issued.
- 4How many domains and scripts does your page load? Check declared limits, such as domains per namespace, and how the tool treats renamed scripts.
- 5How does the evidence leave the tool? The report for requirements 6.4.3 and 11.6.1 has to reach the QSA with inventory, approvals and change history.
Frequently asked questions
What is the best alternative to F5 Client-Side Defense?
It depends on where the application runs and what the checkout accepts. Teams on Cloudflare or Akamai find equivalent modules on their own platform. Teams that want to watch every shopper on any infrastructure look at Feroot and c/side. For UPI, PromptPay, PayNow, Pix, bank slips and stablecoins, payment verification appears in Proteside's public documentation.
What does an alternative to F5 Client-Side Defense need to cover?
An inventory of first-, third- and fourth-party scripts, recorded approvals, alerts on field reads and header changes, and evidence for requirements 6.4.3 and 11.6.1. If the checkout takes more than cards, add recipient verification and blocking in every session.
Who are F5 Client-Side Defense's competitors?
In the same family of CDN and WAF modules, Cloudflare Client-Side Security, Akamai Client-Side Protection & Compliance and Imperva. Among in-page agents, Feroot, c/side, Jscrambler, Source Defense and HUMAN Security. In external monitoring, Reflectiz and SecurityMetrics. Proteside compares itself with all of them on these pages.
Does Proteside replace F5 Client-Side Defense?
It depends on what you use F5 for. On the payment page, Proteside covers the script inventory and requirements 6.4.3 and 11.6.1, and adds payment verification with automatic blocking. If the team wants to keep alerts in the Distributed Cloud console alongside the rest of the application, the two tools can coexist.
All guides
- Feroot alternatives
- c/side alternatives
- Jscrambler alternatives
- Source Defense alternatives
- HUMAN Security alternatives
- Reflectiz alternatives
- SecurityMetrics alternatives
- Cloudflare Page Shield alternatives
- Akamai Client-Side Protection alternatives
- Imperva Client-Side Protection alternatives
- All comparisons
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