cside
cside is a cybersecurity company founded in 2024 that provides a client-side security platform detecting script attacks, AI agents, account takeover, and fraud at the browser layer, with automated PCI DSS 4.0.1 compliance, serving eCommerce, Crypto, Payments, and SaaS customers.
- Company typePrivate
- Founded2024
- HeadquartersDover, United States
- Headcount11–50
- GTM typeB2B
- OfferingSoftware
What cside does
cside (legally Client-Side Development, Inc., incorporated in Delaware and headquartered in San Francisco) is a venture-backed cybersecurity company founded in May 2024 that provides a client-side security platform monitoring third-party scripts executing inside end-user browsers. The platform is deployed via a single JavaScript snippet added to the page head, with no reverse proxy, CDN, or DNS changes, and operates by monitoring 100% of real visitor sessions without sampling. Scripts are downloaded to cside infrastructure for server-side analysis invisible to attackers, with every payload archived for forensics and PCI evidence. The core technology stack combines browser-layer behavioral monitoring, a proprietary 102-signal device fingerprinting engine reporting 99.7% accuracy across VPNs and incognito mode, multi-layered OSI (layers 3/4/7) VPN detection, and AI-driven classification of agentic traffic from AI-powered browsers and automation frameworks.
The product portfolio centers on four core offerings: Client-Side Security (script monitoring), PCI Shield (automated PCI DSS 4.0.1 requirements 6.4.3 and 11.6.1 compliance, VikingCloud QSA-validated), AI Agent Detection, and Fingerprint. Modular add-ons include Privacy Watch (GDPR/CPRA/HIPAA privacy compliance), Chargeback Evidence (Chargebacks911-integrated dispute packages), Device-Bound Sessions (session replay ATO prevention), CSP management, and Applicant Check (ATS fraud screening). cside pursues a hybrid go-to-market: PLG freemium with a free tier at 2,500 payment page views/month and a $99/month Business tier, layered with direct enterprise sales for custom contracts including SSO, 99.9% uptime SLA, multi-year terms, and AWS Marketplace billing.
Customer segments span eCommerce, Crypto/DeFi, Payment Providers, and SaaS Platforms as primary verticals, with Airlines, Gaming/Betting, Hospitality, and Healthcare/Telemedicine as secondary. The company has raised $7.7 million in total across a $1.7M pre-seed (May 2024, Scribble Ventures) and $6M seed (September 2024, Uncork Capital lead), is SOC 2 Type II certified, maintains a PCI DSS Attestation of Compliance, and has won multiple G2, SourceForge, and industry awards in 2025-2026.
cside firmographics
Firmographics- Name
- cside
- Legal name
- Client-Side Development, Inc.
- Website
- https://cside.com
- Company type
- Private
- Founded year
- 2024
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- cside is a cybersecurity company founded in 2024 that provides a client-side security platform detecting script attacks, AI agents, account takeover, and fraud at the browser layer, with automated PCI DSS 4.0.1 compliance, serving eCommerce, Crypto, Payments, and SaaS customers.
- Ownership category
- akta.pro rank
cside industry classification
Industry- Product category
- Client-Side Security
- NAICS
- Security Systems Services (except Locksmiths) (561621)
- akta.pro primary industry
- Payments Fraud & Chargeback Prevention (HDADALAE)
- akta.pro secondary industry
- Fraud Detection & Transaction Monitoring (FSAMALAA)
Keywords
Where cside is headquartered
LocationHeadquarters
- HQ city
- Dover
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
cside business model
Business model- GTM type
- B2B
- Offering type
- Software
- Cost components
- Technology or R&D, Personnel, Marketing or Sales, Infrastructure, Operations
Revenue model
- Script Security Subscription: Subscription-based pricing for client-side script security monitoring. Free tier with 2,500 payment page views/month, Business tier at $99/month for up to 100,000 payment page views, Enterprise tier with custom pricing and SLA. Revenue scales with payment page view volume.
- Fingerprinting Subscription: Browser fingerprinting and device identity platform. Free tier with 1,000 API calls/month, Business tier at $99/month with advanced intelligence signals including AI agent detection and VPN detection, Enterprise tier with custom pricing for chargeback fingerprinting.
- Enterprise Professional Services: Dedicated implementation engineer, custom data retention, SSO, multi-team organization layer, and custom SLA for enterprise customers.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Freemium | Monthly | Free Script Security - Up to 2,500 payment page views/month with PCI DSS 6.4.3 and 11.6.1 |
| Subscription | Monthly | Business Script Security - Up to 100,000 payment page views with full PCI DSS 4.0.1 compliance |
| Subscription | Multi-year contract | Enterprise Script Security - Custom limits with 99.9% uptime SLA and dedicated support |
| Freemium | Monthly | Free Fingerprint - Up to 1,000 API calls/month with basic device fingerprinting |
| Subscription | Monthly | Business Fingerprint - $99/month with all intelligence signals including AI agent detection |
| Subscription | Multi-year contract | Enterprise Fingerprint - Custom pricing with chargeback evidence and custom data retention |
Go-to-market motion2 records
Distribution channels3 records
Marketing channels9 records
cside product offering
Product offeringCore offering
cside operates a client-side security platform delivered via a single JavaScript snippet that monitors every third-party script executing in visitor browsers in real time, detects Magecart/web-skimming attacks, abusive AI agents, and account-takeover activity at the browser layer, and automates PCI DSS 4.0.1 requirements 6.4.3 and 11.6.1 with QSA-validated reporting. The platform also provides device fingerprinting with 102+ behavioral signals, VPN detection, AI agent detection, privacy compliance monitoring (GDPR/CPRA/HIPAA), and chargeback evidence capture integrated with Chargebacks911.
Product overview
cside is a client-side security platform providing browser-layer visibility and protection through a unified platform architecture. The core offerings consist of Client-Side Security (monitoring scripts in 100% of visitor sessions), PCI Shield (automated PCI DSS 4.0.1 compliance), AI Agent Detection (identifying autonomous traffic), and Fingerprint (device fingerprinting with 102+ signals). These core products are complemented by modular add-ons including Privacy Watch (AI-powered privacy compliance), VPN Detection (network analysis), Device-Bound Sessions (ATO prevention), CSP management, Applicant Check (fraud detection), and Chargeback Evidence (dispute support). The platform deploys via a single JavaScript snippet with no infrastructure changes, operates inside the browser without proxy or CDN dependency, and serves industries including eCommerce, crypto, payments, SaaS, airlines, gaming, hospitality, and healthcare.
Differentiator
Problem solved
Functional benefit
Products and services
- Client-Side Security Full client-side security platform that monitors every third-party script executing in 100% of visitor sessions with no sampling; detects Magecart (a class of attacks that inject malicious code into online checkout pages), web skimming, e-skimming, formjacking, and data exfiltration attacks at the browser layer before the server registers the event.
- PCI Shield Automated PCI DSS (Payment Card Industry Data Security Standard) 4.0.1 compliance solution for requirements 6.4.3 and 11.6.1 that inventories every script on payment pages, generates AI-written justifications, produces audit-ready reports on demand, and is validated by VikingCloud QSA.
- Fingerprint Device fingerprinting product with 99.7% accuracy across sessions, VPNs, and incognito mode; exposes 102+ browser, device, and behavioral signals for fraud prevention, account takeover detection, and chargeback evidence capture.
- AI Agent Detection Detection toolkit that identifies agentic traffic from both cloud-hosted automation and AI-powered browsers running on consumer devices; detects OpenAI Operator, Claude for Chrome, Puppeteer, Playwright, and Selenium.
- Privacy Watch Real-time client-side data management and privacy policy enforcement platform using AI to monitor third-party script data interactions; assists organizations with GDPR (General Data Protection Regulation), CPRA (California Privacy Rights Act), and HIPAA (Health Insurance Portability and Accountability Act) compliance through automated risk detection, documentation, and reporting.
- VPN Detection Detection solution using multi-layered OSI network analysis (layers 3, 4, and 7) to identify VPN traffic based on browser fingerprints, device characteristics, and network behavior; addresses compliance requirements for the UK Online Safety Act and US state legislation.
- Chargeback Evidence Session-level evidence capture at transaction time including device fingerprints, browser session timelines, script activity logs, and behavioral signals; pre-built evidence packages exportable in seconds for Visa CE 3.0 (Cardholder Evidence 3.0) and Mastercard chargeback programs with direct integration to Chargebacks911.
Quantifiable outcome
- 40% average increase in dispute win rates for merchants using cside for chargeback evidence (platform data, 2024-2025)
- +4 more outcomes
Companies that use cside
Customer profileNamed customers6 records
Segments8 records
Ideal customer profiles4 records
cside technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- Yes
- API docs
- API detail
Core technology
AI maturity
App detail
Integration18 records
AI capability5 records
Feature8 records
cside partnerships and signals
Strategic signalPartnerships
Ten partnerships are on record, tiered core integration, strategic partner, partner, integration, infrastructure and channel.
- Chargebacks911core integrationDirect integration with Chargebacks911 for end-to-end dispute management. cside captures device fingerprints tied to order IDs and formats pre-built evidence packages meeting CB911's submission requirements.
- VikingCloudstrategic partnerVikingCloud, a leading QSA firm, validated cside's PCI DSS 4.0.1 solution for requirements 6.4.3 and 11.6.1. Joint webinars conducted for customer education on compliance.
- BARR AdvisorypartnerConducted joint webinar on what auditors expect to see for PCI 6.4.3 and 11.6.1 compliance requirements.
- MegaplanITpartnerConducted joint Q&A session with QSA on PCI DSS requirements 6.4.3 and 11.6.1 implementation.
- VantaintegrationIntegration with Vanta compliance platform for automated compliance monitoring and evidence collection.
- DrataintegrationIntegration with Drata compliance platform for automated compliance monitoring and evidence collection.
- StripeinfrastructurePayment processor for cside's own billing. Stripe processes payment card data and transaction data for site payments.
- HubSpotinfrastructureMarketing automation and customer support integration. HubSpot is used for marketing emails, form tracking, and customer communication.
- PosthoginfrastructureSession replay and analytics for cside's own product. Posthog records user interactions for usability analysis and product improvement.
- AWSchannelAWS Marketplace listing for enterprise billing. Customers can procure cside through their AWS Marketplace subscription.
Scale indicators8 records
Recent moves6 records
Expansion highlights6 records
cside competitors and assessment
Company assessmentBroad incumbents
- Akamai (Bot Manager / Client-Side Protection): Akamai offers Bot Manager and client-side protection capabilities as part of its broader application security portfolio. While not focused exclusively on browser-side script monitoring, it overlaps with cside in bot management, account takeover prevention, and payment fraud protection for large enterprise customers.
- Imperva (Client-Side Protection): Imperva provides application and data security, including bot management and client-side protection capabilities. As a broader security incumbent, it competes with cside in fraud prevention and account takeover protection for enterprise customers.
- F5 Shape Security: F5 Shape Security provides anti-bot, fraud prevention, and account takeover protection as part of F5's broader application security portfolio. It overlaps with cside in fraud detection and credential abuse prevention for large enterprise and financial services customers.
Direct peers
- HUMAN Security: HUMAN Security (formerly White Ops, which acquired PerimeterX) provides bot management, account takeover prevention, and client-side application protection. It directly competes with cside in fraud prevention at the browser layer and serves similar ecommerce, SaaS, and financial services customers.
- DataDome: DataDome offers bot protection, online fraud prevention, and account takeover detection. It overlaps with cside in real-time detection of malicious automation and fraudulent sessions at the application layer, serving ecommerce and digital platform customers.
- Source Defense: Source Defense focuses specifically on client-side web application security, including Magecart attack prevention and third-party script monitoring. It is one of the most direct competitors to cside's core Client-Side Security and PCI DSS compliance offerings.
- Reflectiz: Reflectiz provides website supply chain security through continuous monitoring of third-party scripts, web skimming detection, and Magecart prevention. It competes directly with cside in browser-side script security and PCI DSS compliance for ecommerce and payment-processing customers.
- Jscrambler: Jscrambler offers client-side application security including JavaScript protection, Magecart prevention, and PCI DSS compliance. It overlaps with cside in script monitoring, web skimming prevention, and compliance automation for payment pages.
- PerimeterX (now HUMAN): PerimeterX was acquired by HUMAN Security but its client-side protection capabilities continue to compete directly with cside. Both focus on browser-layer script monitoring, bot mitigation, and account takeover prevention for digital businesses.
Emerging players
- Castle.io: Castle.io provides account takeover prevention, device fingerprinting, and fraud detection for web and mobile applications. It overlaps with cside's Fingerprint and Device-Bound Sessions modules, particularly around browser-layer identity and fraud signals.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat6 records
Key risks5 records
Key highlights7 records
Customer concentration
cside social profiles
Digital presencecside compliance and trust
Trust signalCompliance5 records
cside financial estimates
Financial estimateRevenue estimate
Valuation estimate
cside leadership team
Management profileNumber of profiles
Profiles1 record
cside funding detail
Funding detailFunding overview
Funding rounds2 records
Investors6 records
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
cside M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about cside
What does cside do?
cside operates a client-side security platform delivered via a single JavaScript snippet that monitors every third-party script executing in visitor browsers in real time, detects Magecart/web-skimming attacks, abusive AI agents, and account-takeover activity at the browser layer, and automates PCI DSS 4.0.1 requirements 6.4.3 and 11.6.1 with QSA-validated reporting. The platform also provides device fingerprinting with 102+ behavioral signals, VPN detection, AI agent detection, privacy compliance monitoring (GDPR/CPRA/HIPAA), and chargeback evidence capture integrated with Chargebacks911.
Is cside a public or private company?
cside is a private company. It is classified as venture growth investor backed and is currently operating.
When was cside founded?
cside was founded in 2024. It employs 11 to 50 people.
Where is cside based?
cside is headquartered in Dover, United States, in the North America region.
How does cside make money?
Three revenue lines are on record. Script Security Subscription is the primary driver. The others are fingerprinting Subscription and enterprise Professional Services.
Who are cside's main competitors?
Broad incumbents on record are Akamai (Bot Manager / Client-Side Protection), Imperva (Client-Side Protection) and F5 Shape Security. Direct peers are HUMAN Security, DataDome, Source Defense, Reflectiz, Jscrambler and PerimeterX (now HUMAN). Castle.io is listed as an emerging player.
Does cside have an API?
Yes. cside provides a public API for device fingerprinting and client telemetry. The Fingerprint product uses an Events API where sendClientTelemetry counts as one API call per request. Pricing includes API call limits (1,000 free/month, 50,000 on Business plan). Real-time alerts can be sent via webhooks to Slack, Teams, email, or custom webhook endpoints. Script Security monitors every third-party script in 100% of visitor sessions with no sampling. Detection signals include bot detection, VPN detection, browser tampering, incognito mode, AI agent detection (OpenAI Operator, Claude for Chrome, Puppeteer, Playwright, Selenium). Developer documentation is at docs.cside.com.
What industry is cside in?
cside's product category is Client-Side Security. Its primary akta.pro industry code is HDADALAE, Payments Fraud & Chargeback Prevention, with a secondary code of FSAMALAA, Fraud Detection & Transaction Monitoring. Its NAICS code is 561621.