AppSignal
Error tracking and performance monitoring that just works
Founded
2012
Starting Price
$0
Category
Developer Tools
Last updated August 17, 2026
About AppSignal
AppSignal is an all-in-one application performance monitoring (APM) platform that combines error tracking, performance monitoring, logging, host and uptime monitoring, cron check-ins, and custom dashboards in a single tool. It is built for backend developers, with first-party instrumentation for Ruby, Elixir, Node.js, Python, and frontend JavaScript, plus OpenTelemetry support for other languages. Pricing is based on request volume rather than per-seat, so every plan includes unlimited users, teams, applications, and dashboards.
Pros & Cons
Pros
- Every monitoring feature is included on every paid plan - errors, performance, logs, hosts, uptime, check-ins, and dashboards are not gated behind higher tiers
- Priced on request volume with unlimited users, teams, applications, and dashboards, so adding engineers costs nothing
- No overage billing: monitoring keeps running past your plan limit and an upgrade conversation only starts after you exceed it in 2 out of 3 months
- Deep first-party instrumentation for Ruby/Rails, Elixir/Phoenix, Node.js, Python, and frontend JavaScript rather than generic agents, with roughly a 2-minute install
Key Features
Error tracking
Captures every exception with backtrace, occurrence history, and the deploy that shipped it. Errors are grouped so you see patterns instead of noise, and can be tagged with custom data, filtered, and pushed to your issue tracker.
Performance monitoring
Tracks response times, throughput, and slow endpoints from the first deploy, with duration breakdowns, event timelines, slow query and N+1 query detection, and memory leak detection.
Log management
Full-text search and attribute filtering across all logs with saved queries, live tail streaming from every service, source and hostname management, and customizable views. Included free up to 1GB/month, paid add-on beyond that.
Trace-linked logs and log-based alerts
Jump from an error straight to the exact log lines that led to it, with timestamps already correlated. Alerts can fire on any log pattern, error string, or warning spike.
Distributed tracing (beta)
Traces requests end-to-end across services to show which call or hop is the bottleneck. Still marked BETA on the platform.
Host monitoring
Server-level metrics including CPU usage, disk I/O and usage, load average, memory and network usage, with side-by-side host comparison.
Pricing
Free
$0/month
- 50K requests/month
- 1GB logging/month
- 5-day retention
- Unlimited users, teams, applications, and dashboards
- No credit card required
Best For
Consolidating a multi-vendor monitoring stack
Teams running separate tools for errors, APM, and logs can replace three or four vendors with one subscription, since AppSignal bundles error tracking, performance monitoring, logging, host metrics, and uptime checks at a single price.
Rails and Phoenix teams that want framework-aware monitoring
First-party integrations understand Active Record, Sidekiq, Puma, GraphQL, Phoenix, Ecto, and Oban, surfacing slow queries and N+1 problems in terms of the framework rather than generic spans.
Small engineering teams priced out of per-seat APM
Because billing is tied to request volume and users are unlimited, a 3 to 25 engineer team can put everyone in the monitoring tool without the seat costs that make Datadog or New Relic expensive at that size.
