AppSignal vs Skylight
AppSignal
appsignal.comSkylight
skylight.ioSide by side
| Figure | AppSignal | Skylight |
|---|---|---|
| Price from | $23.25/mo | $20/mo |
| Free plan | Yes | Yes |
| Free trial | Yes | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| API | Yes | Yes |
| Plans published | 2 | 3 |
| Spec score · Application Performance Monitoring | 8.6 (#4) | 7.8 (#23) |
| Product | AppSignal is an all-in-one application monitoring product for developers, with error tracking and performance monitoring. | Skylight is a smart profiler for Ruby and Rails applications that turns performance data into actionable insights. |
| Support | AppSignal says customers can contact a real engineer through live chat or support email. | Skylight provides documentation for setup, instrumentation, performance tips, background jobs, and troubleshooting, and directs users with further questions to contact support. |
| Trial | The site offers a 30-day full-featured trial and says no credit card is needed. | The signup page offers a free month, and the pricing page says no credit card is required to try Skylight. |
Plans
In their own words
AppSignal
AppSignal is a cloud application-monitoring service for developers, with error tracking, performance monitoring, logs, and tracing. Error tracking groups exceptions with backtraces and the deployment linked to each issue. Performance monitoring covers response times, throughput, slow endpoints, and slow queries. Log management provides full-text search, attribute filters, saved queries, live tail, and pattern-based alerts. Distributed tracing, transaction tracing, and log correlation are available. AppSignal lists support for Ruby, Elixir, Node.js, JavaScript, Python, Go, Java, PHP, and Rust, with integrations including Slack, GitHub, Jira, Linear, GitLab, and PagerDuty. Its MCP server lets AI assistants such as Claude, Cursor, and Zed query production errors, traces, and deploys. The free plan costs nothing and includes 30K requests, 1GB logging, five-day retention, and unlimited users, teams, applications, and dashboards. Paid access is $279 a year, billed yearly at $23.25/month, with 250K requests per month. A 30-day full-featured trial requires no credit card. AppSignal says it does not charge overages or stop monitoring when limits are crossed.
Skylight
Skylight is a cloud profiler for Ruby and Rails applications, available through API, Linux, macOS, and web platforms. It ranks endpoints by “agony,” combining popularity with response time, and plots deployments against performance so teams can relate code changes to results. Supported Ruby frameworks include Rails, Sinatra, and Grape. Skylight analyzes Sidekiq, DelayedJob, and ActiveJob background queues, and can flag allocation-heavy code and repeated queries. Endpoint timelines present aggregated, sanitized SQL queries. GraphQL queries are grouped by name in the dashboard and endpoint event sequences. A weekly report identifies improved endpoints, slowdown warnings, and endpoints that declined over six weeks. Each account includes 100,000 free traces per month. Paid tiers start at $20 a month and adjust to monthly trace volume across apps. A 30-day trial is available without a credit card. Open-source apps may apply for free public reporting. Communications are encrypted, and access to customer information is limited to selected personnel and contractors.