Sandeep PandaUpdated Jun 10, 2026Test Every Flow.
Break Nothing.
End-to-end functional testing for web applications. AI-powered and human-verified, with results in your pull requests and Slack.
Results in your first week. Managed AI QA with Forward-Deployed Engineers from $2,500/mo.
Featured in Google AI Studio's developer showcasefeat: new billing plans #847
jordan wants to merge 3 commits into main
- bug0 / critical-flows— 47 tests passed4m 12s
- bug0 / pr-smoke— 12 tests passed58s
- bug0 / regression-nightly— 214 tests passed11m 03s
- 100%
- of critical flows in 1–2 weeks
- 4 weeks
- to full coverage
- <5 min
- for hundreds of parallel tests
- 0
- scripts your team writes
- Every PR
- checked in GitHub and Slack
- Self-healing
- tests adapt when UI changes
Functional Testing
What are functional testing services?
Feature validation
Functional testing services verify that each feature and user flow behaves as intended across your web app, sign in, checkout, permissions, forms, and more. A provider builds, runs, and maintains a reliable suite that covers real user journeys.
Why Bug0?
Bug0 acts like your AI QA Engineer. We deliver AI-powered functional testing services for web apps, set up end-to-end browser tests in days, keep them stable release after release, and surface verified results in pull requests and Slack.
Types of functional testing we cover
Seven test packs cover the flows that break most often. Each one runs on every pull request, not on a quarterly cycle.
- Smoke testing and happy paths
Quick checks that core features still work after every deploy. We cover the paths users take most often, so sign in, search, and checkout never break silently.
Example: after each deploy, a smoke pack confirms users can sign in, load the dashboard, and reach checkout.
- Regression testing services on every change
Every code change runs against the existing suite. Features that worked last week still work after Friday's merge.
Example: a pricing page refactor triggers the full regression suite before the PR merges.
- Authentication and authorization flows
Login, logout, SSO, role-based access, and permission systems. Users see exactly what their role allows and nothing more.
Example: an admin invites a viewer, and the test confirms the viewer cannot edit billing.
- Payments, carts, subscriptions, refunds
The full purchase journey, from cart to charge. Upgrade and downgrade paths, coupon codes, and refund flows included.
Example: a test subscribes to a monthly plan, upgrades to annual, then requests a refund.
- File uploads and downloads
Uploads across file types, sizes, and formats, plus the error states when they fail. Downloads verified end to end.
Example: a large PDF upload, a rejected file type, and a CSV export each get their own test.
- Forms, validations, and error states
Every form state tested. Submissions, field validations, error messages, and edge cases, so users get clear feedback instead of silent failures.
Example: a signup form is tested with a bad email, a weak password, and a double submit.
- Admin dashboards and multi tenant flows
Admin panels, user management, and tenant data isolation. One tenant's data never leaks into another's dashboard.
Example: a test creates two tenants and confirms tenant A never sees tenant B's records.
Run #1284 · main
2 minutes ago
- ✓Smoke12/1258s
- ✓Critical flows47/474m 12s
- ✓Auth & permissions18/182m 04s
- ✓Payments9/91m 41s
- ✗Regression (nightly)212/21411m 03s
2 failures verified by your FDE · 1 real bug filed · 1 test data issue fixed
How Bug0 functional testing works
Six steps from kickoff to a green check on every pull request. Your engineers write nothing.
- 01
Your engineer maps your app
Your FDE explores your flows with Bug0's agents, discovers states, and captures the elements that matter. No test plan required from your team.
- 02
Tests are generated
Your FDE generates end-to-end browser tests that mirror real user behavior, as plain-English steps on Passmark, our open-source engine.
- 03
Self-healing
When your UI changes, tests adapt instead of breaking. Brittle locators never block a release.
- 04
Massively parallel runs
Hundreds of browser tests finish in under 5 minutes. Fast enough to run on every commit.
- 05
Human verification
QA experts review edge cases and validate results, so a pass means a pass.
- 06
CI and CD native
Results arrive as GitHub checks, pull request comments, and Slack reports. Nothing for your team to babysit.
✓ Functional pack passed — 47 tests in 4m 12s.
- 2 steps auto-healed (checkout button markup changed)
- 0 flaky retries · all assertions agreed on first pass
View full report →
What you get
100% of critical flows covered in 1–2 weeks
Full coverage of your application in 4 weeks
Zero maintenance hours spent by your engineers
Reporting in GitHub and Slack after every run
No long-term commitment month to month, cancel anytime
Bug0 vs other functional testing services
See how Bug0's AI-powered approach compares to traditional functional testing providers.
| Feature / Vendor | Rainforest QA | Testlio | Applause | Global App Testing | |
|---|---|---|---|---|---|
Test creation | AI auto generates tests, human verified | No code with AI assist, service team builds suites | Human testers with some automation | Manual testers with limited automation options | Crowd testers, exploratory focus |
Maintenance | Self healing, zero upkeep for your team | Service team updates tests | Manual updates by test managers and freelancers | Manual updates within programs | Manual updates tied to tester cycles |
Speed to coverage | Critical user flows in 1–2 weeks | Weeks to months | Weeks, tied to scheduling | Weeks, depends on program cadence | Fast exploratory passes, limited for daily pull requests |
Execution | Hundreds of parallel browser tests in less than five minutes | Platform runs with service oversight | Cases executed by a tester network | Large global crowd executes cases | Global tester pool runs checks |
Verification | AI plus human QA experts | Human testers | Human testers | Human testers | Human testers |
Setup | Zero setup, CI and CD ready | Requires onboarding | Requires onboarding | Requires onboarding | Requires onboarding |
Scalability | Unlimited parallel runs, AI driven | Limited by service capacity | Limited by freelancer availability | Large tester pool, program managed | Large tester pool |
Best fit | Teams that want continuous QA on every pull request | Teams that want one vendor for platform and services | Apps that need many real devices and payment paths | Consumer apps, localization, and UX studies | Quick global checks across markets |
Swipe horizontally to see all comparisons
Who uses functional testing services
Common buyers are the CTO, VP of Engineering, Head of QA, Staff Engineer, or Engineering Manager. The teams below get the most out of it.
- Product-led SaaS teams
Ship daily or weekly without a QA bottleneck. Every release gets the same functional pass, no matter how fast you move.
- Early stage teams
Coverage without a QA hire. One subscription instead of a first QA engineer.
- Ecommerce teams
Checkout, subscriptions, and refunds tested on every change. A broken cart costs revenue by the hour.
- Fintech and banking products
KYC, transfers, and role-based access. Flows where a regression is a compliance problem, not just a bug.
- Healthcare portals and patient apps
Compliance and reliability requirements that manual spot checks cannot meet.
- Marketplaces
Buyer and seller flows with layered permissions, tested from both sides in the same run.
- Internal tools and admin dashboards
Safe regression coverage for the tools your own team depends on.
- B2B platforms
Third-party integrations and webhooks verified end to end.
- Enterprises
Functional testing with clear SLAs, one dedicated forward-deployed engineer, and SOC 2 compliance.
Pricing
Managed AI QA with Forward-Deployed Engineers. Book a call to get started.
Managed
Your dedicated AI QA engineer
A forward-deployed engineer plus AI that reasons through your UI. It maps your flows, handles 2FA, and re-resolves steps from intent when your UI changes, before you even get the Slack alert.
Passmark
The library that powers Managed
The Playwright library your FDE uses to write your tests. Open source. Read the code. See exactly how your suite is built.
What engineering leaders say.
“Bug0 is the AI QA platform behind Prospyr, the practice management software for aesthetics clinics. It tests our web app continuously and points us to exactly where the app broke when something fails. We catch issues early instead of in production, which keeps a HIPAA-compliant product stable.”
“Bug0 is the closest thing to plug-and-play QA testing at scale. It's helped us catch multiple bugs before they made it to prod.”
“We build healthcare compliance software, so accuracy and reliability are non-negotiable. Bug0 provided us with an AI-based QA layer without adding headcount or another tool for my team to learn and manage. The tests run against all of our QA instances on a regular basis, providing us with a level of coverage and confidence that previously required many resources. We can focus our team on new development and real issues, and that's the part I care most about.”
“We plugged Bug0 into our CI and had our critical flows covered within a week. Like having a proactive QA engineer reviewing every deploy.”
“Bug0 is the AI QA platform behind Ferra, AI estimating software for steel construction. AI-based testing and execution with a forward deployed engineer who verifies every result, so we catch real bugs before production instead of chasing false positives. We see exactly where things broke, and we ship with confidence.”
“Bug0 gives us the speed of AI-native automation with the accuracy of human QA. We stopped worrying about flaky tests entirely.”
“We'd been putting off test coverage for months. Bug0 had our critical flows covered in under a week. No scripts, no maintenance burden.”
“We used to skip regression tests before releases because they took too long to maintain. Bug0 runs them on every PR now. We haven't shipped a regression in three months.”
Outcomes, not overhead.
Bug0 is more than a tool. It's your AI QA Engineer.
Built by your engineer. Run and healed by AI. Every result verified. You ship faster without hiring.
Frequently Asked Questions
Product led SaaS teams that ship weekly.
Ecommerce teams that manage checkout, subscriptions, and refunds.
Fintech and banking products with KYC, transfers, and role based access.
Healthcare portals and patient apps that require compliance and reliability.
Marketplaces with buyer and seller flows and complex permissions.
Internal tools and admin dashboards that need safe regression coverage.
B2B platforms that integrate third party providers and webhooks.
Common buyers include CTO, VP of Engineering, Head of QA, Staff Engineer, and Engineering Manager.