c/side alternatives for protecting the payment page (2026)
By Laís Peixoto
Growth Marketer, Proteside
Published
Teams looking for c/side alternatives find three families: in-page agents such as Feroot and Jscrambler; external monitors such as Reflectiz and SecurityMetrics; and CDN or WAF modules such as Cloudflare Client-Side Security (formerly Page Shield). Proteside takes a fourth route and verifies the payment itself on top of the scripts. The choice starts with what your checkout accepts.
Why teams evaluate other options
The checkout accepts more than cards
UPI, PromptPay, PayNow, bank slips and stablecoins have no card form to guard. Web skimming here means swapping the payee on screen or in the clipboard, which calls for comparing the displayed data with what was issued.
Blocking has to be automatic
When the swap happens inside a single session, an alert reviewed later arrives too late. Teams want the block before confirmation, without waiting for someone to open a dashboard.
Protection and evidence from the same tool
Small and mid-sized operations want proof for requirements 6.4.3 and 11.6.1 coming out of the tool that stops the fraud, ready for the QSA.
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. | c/side 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 |
| Jscrambler Webpage Integrity | A JavaScript agent, or synthetic-user monitoring, inventories scripts, detects behavioral drift and enforces blocking and form protection policies; a module covers requirements 6.4.3 and 11.6.1. | Companies that also need to protect their own JavaScript code (obfuscation), and payment providers that serve checkout pages in iframes. | Jscrambler 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 |
| SecurityMetrics Shopping Cart Monitor | Scans the payment page from outside, at intervals, simulating the checkout, and alerts on new scripts and changes; the company itself describes the product as a detection tool and says it was not built to prevent. | Merchants already using the SecurityMetrics PCI portal (questionnaires, ASV scans) who want evidence for requirements 6.4.3 and 11.6.1 in the same place. | SecurityMetrics 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 |
Choose the category before the vendor
Before swapping one vendor for a similar one, look at the category. In-page agents such as c/side, Feroot and Jscrambler see every real session and control what runs; external monitors such as Reflectiz and SecurityMetrics deliver the inventory with no code on the site, at the cost of not seeing each buyer; CDN or WAF modules such as Cloudflare's act at the edge and depend on traffic passing through it. All three families grew out of the card problem and meet requirement 6.4.3 in different ways.
None of them, as far as their public documentation describes, checks whether the QR code, payee ID, slip line or wallet address on screen is the one the merchant issued. c/side comes closest by naming the swapped clipboard address on its crypto page, but without a comparison against what was generated. That comparison is Proteside's category: it includes the script inventory and the PCI DSS evidence and adds payment verification.
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.
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.
Jscrambler Webpage Integrity
Jscrambler brings together two distinct products: Code Integrity, for protecting and obfuscating JavaScript code, and Webpage Integrity, for inventorying and controlling scripts on the page, with a PCI DSS compliance module. Public documentation describes an agent mode, which blocks in real sessions, and an agentless mode, which simulates a user.
It is a mature offer for teams with cards as the main payment method who want a single company for code and page. The public material does not address Pix, boleto (Brazilian bank slip), instant payment QR codes or crypto wallets.
Jscrambler is the right choice when: you need to protect your own JavaScript code beyond the payment page, or you are a provider that delivers checkout in an iframe.
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.
SecurityMetrics Shopping Cart Monitor
SecurityMetrics is a PCI assessment company (QSA, ASV) and Shopping Cart Monitor fits into its portal: script inventory with justification, detection of content and header changes, alerts and an exportable log for the assessor, with nothing installed on the site.
The public material is candid about the limit: the tool was built to detect, the vendor says, and it works from snapshots taken at intervals. For teams that need the scam blocked while the customer is still on the page, the approach works as a complement to a real-session block.
SecurityMetrics is the right choice when: your PCI DSS assessment already goes through SecurityMetrics and you want payment page evidence integrated into the same portal.
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.
How to evaluate an alternative
- 1Which payment methods does your page display? If there is UPI, PromptPay, PayNow, a bank slip or a wallet address, the tool has to compare that data with what your server issued.
- 2What happens inside a single compromised session? Automatic block before confirmation, or an alert for someone to review?
- 3Can you place a script tag on the payment page? If not, only external monitors fit, with the limits they themselves state.
- 4Who receives the alert and where? Slack, Teams, email and webhooks usually suffice for small teams; SIEM feeds matter for larger operations.
- 5Does the report come out ready for the QSA, with inventory, authorizations and change history for requirements 6.4.3 and 11.6.1?
- 6Does your operation depend on a specific CDN? Edge modules only work for sites already on that platform.
Frequently asked questions
What is the best alternative to c/side?
It depends on what your checkout accepts. For cards with script control, Feroot and Jscrambler cover similar ground; Reflectiz and SecurityMetrics serve teams that cannot add code to the page; Cloudflare Client-Side Security serves sites already behind Cloudflare. For UPI, PromptPay, bank slips, stablecoins and other non-card methods, payment verification appears only in Proteside's public documentation.
What does a c/side alternative need to cover?
At a minimum, observe real sessions, inventory and authorize scripts, detect changes to the page and its headers, and produce a report for the auditor. If the checkout goes beyond cards, add a comparison of the displayed payee with the issued one.
Who are c/side's competitors?
In the same in-page agent family, Feroot, Jscrambler, Source Defense and HUMAN Security. In external monitoring, Reflectiz and SecurityMetrics. In CDN and WAF modules, Cloudflare, Akamai, Imperva and F5. Proteside compares itself with all of them on these pages.
Does Proteside replace c/side?
It depends on what you use it for. On the payment page, Proteside covers inventory, script blocking and requirements 6.4.3 and 11.6.1, and adds payment verification. Fingerprint's device identification and bot detection are outside Proteside's scope; in that case the two tools run side by side.
All guides
- Feroot 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
- F5 Client-Side Defense alternatives
- All comparisons
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