ToolStack

FullStory vs Optimizely

Side-by-side comparison · Updated 2026-03-30

Our VerdictFullStory wins overall

By G2 score and review volume, FullStory has the edge. 900 reviews at 4.5/5 puts it ahead of Optimizely (4.2/5). That said, the right pick depends on your methodology and team size.

Choose FullStory if…

Choose FullStory if your team focuses on session replay and user behavior analysis and fits a startup, scaleup profile. Free tier available. Best-in-class autocapture technology — captures every click, scroll, and interaction without manual event tagging, enabling retroactive analysis on historical data

Choose Optimizely if…

Choose Optimizely if your team focuses on ab testing and feature flagging and fits a scaleup, enterprise profile. Usage-based pricing — contact for a quote. Industry-leading experimentation platform with both client-side and server-side testing — supports the full experimentation lifecycle from hypothesis to results

FullStory
by FullStory
4.5
out of 5 · 900 G2 reviews
Visit FullStory ↗
Optimizely
by Optimizely
4.2
out of 5 · 700 G2 reviews
Visit Optimizely ↗

Feature Comparison

FeatureFullStoryOptimizely
Category
session_replay
ab_testing
G2 Score
4.5 / 5.0Better
4.2 / 5.0
G2 Reviews
900
700
Free Tier
Starting Price
—
—
Mobile App
AI Features
API Access
SSO / SAML
SOC 2
Learning Curve
moderate
moderate
Platforms
web
web, ios, android

Pros & Cons

FullStory

Pros
✓ Best-in-class autocapture technology — captures every click, scroll, and interaction without manual event tagging, enabling retroactive analysis on historical data
✓ Frustration signals (rage clicks, dead clicks, error clicks) surface UX problems automatically, saving PMs hours of manual session review
✓ Powerful search and segmentation — find specific user sessions by any combination of events, user properties, or frustration signals in seconds
✓ Strong privacy-by-design approach with automatic PII masking, excluded elements, and HIPAA-compliant configurations for regulated industries
Cons
✗ No transparent public pricing — Business and Enterprise plans require contacting sales, making budgeting difficult for smaller teams
✗ Session-based pricing can become very expensive at scale, especially for high-traffic consumer products with millions of monthly sessions
✗ Data retention on lower tiers is limited — teams may lose access to historical sessions unless on Enterprise plans

Optimizely

Pros
✓ Industry-leading experimentation platform with both client-side and server-side testing — supports the full experimentation lifecycle from hypothesis to results
✓ Powerful Stats Engine uses sequential testing methodology that allows peeking at results without inflating false positive rates — a significant advantage over traditional frequentist approaches
✓ Robust feature flagging and progressive rollout capabilities allow engineering teams to decouple deployment from release, with fine-grained audience targeting
✓ Visual editor enables non-technical marketers and PMs to create and launch A/B tests without developer involvement for front-end experiments
Cons
✗ Pricing is entirely custom and opaque — typically very expensive, starting in the tens of thousands annually, making it prohibitive for startups and small teams
✗ No free tier for experimentation products — only a limited free Rollouts plan for basic feature flags, unlike competitors such as LaunchDarkly or PostHog
✗ Client-side snippet can introduce page flicker and latency if not carefully implemented, potentially impacting user experience and Core Web Vitals

Frequently Asked Questions

It depends on your needs. FullStory scores 4.5/5 on G2, while Optimizely scores 4.2/5. FullStory is better for session_replay and user_behavior_analysis, while Optimizely excels at ab_testing and feature_flagging.
FullStory starts at N/A per user/month with a free tier. Optimizely starts at N/A per user/month.
FullStory supports 70 integrations, while Optimizely supports 100.
Full FullStory Review →Full Optimizely Review →
Data verified 2026-03-30. Some links may be affiliate links — see disclosure.