Slowpoke vs AppSignal
AppSignal is an APM people tend to like: fair pricing by request volume rather than by host or seat, unlimited applications, and a product that does not punish you for growing your team. It is also hosted, and it still meters the traffic you are trying to reduce.
The short answer
Which one you should pick
If you are going to pay for a hosted APM, AppSignal's pricing is among the most honest on this list. The question is whether you want to pay a meter at all, and whether the application is the whole of your problem.
Choose AppSignal if
You want a hosted APM that does not nickel-and-dime you
- You want errors, performance, host metrics, uptime and dashboards in one hosted product.
- You have several applications and would rather not pay per app or per host. AppSignal charges for neither.
- You are on Ruby, Elixir, Node, Python or PHP and want first-class, well-maintained instrumentation.
- You want anomaly detection and alerting, which Slowpoke does not have.
Choose Slowpoke if
You want no meter, and more than the application
- You do not want the bill to move when traffic does, since traffic is exactly what you are trying to make cheaper.
- Your production data has to stay on machines you control.
- The database server, the PHP-FPM pools, Redis and the queues are part of the problem.
- You want EXPLAIN plans with the index to add, and the line of code that ran the query.
- You need the findings prioritised in business terms, and turned into work that closes itself.
Side by side
Slowpoke and AppSignal, line by line
Written to be fair, including where AppSignal is the better tool. If a row here is wrong or out of date, that is a bug: open an issue and it gets corrected.
| Aspect | Slowpoke | AppSignal |
|---|---|---|
| Price model | €0, self-hosted, no meter | Monthly request volume; a request is a web request or a background job |
| Cost of more hosts or apps | €0 | €0: AppSignal charges for neither |
| Cost of more traffic | €0 | It moves you up a request tier |
| Cost of more engineers | €0 | €0, no seat pricing |
| Entry price | €0 | Around $23 a month; roughly $279 a year at 250,000 requests a month (list, 2026) |
| Where your data lives | Your machines, always | AppSignal's cloud |
| Errors and exceptions | Not its job | Yes, and well done |
| Alerting and anomaly detection | Digests and deploy verdicts only | Yes |
| Prioritised by business cost | Seconds of waiting per day | Slowest first |
| Query plans with a fix | Real EXPLAIN, twelve named diagnoses | No |
| The machine and the database server | CPU, iowait, swap, OOM, disk, Redis, PHP-FPM pools | Host metrics, not database internals |
| Maps what you inherited | One command reads each machine | You install the SDK where you know the apps are |
| Work that verifies itself | Missions closed by measurement | No |
| Read by your coding assistant | Missions over MCP | No |
A fair meter is still a meter
Credit where it is due: AppSignal's pricing avoids the two worst patterns in this market. It does not charge per host, so autoscaling is not a billing event, and it does not charge per seat, so nobody has to decide whether a junior engineer is worth a licence. Unlimited apps and unlimited hosts, priced on request volume, starting around $23 a month.
The remaining friction is structural rather than greedy. A request is counted when your application handles a client request or runs a background job, so the meter runs fastest exactly when your system is busiest, which is the state you bought a performance tool to get out of. Growth, the thing you actually want, is also the thing you are billed for.
Slowpoke has no meter of any kind. It is open source and self-hosted, and the number of requests, queries and jobs it prices has no effect on what it costs you, which is nothing.
Slowest first, against most expensive first
Most APMs, AppSignal included, sort by how slow a single execution was. That is the intuitive ranking and it is the wrong one. A 30-second nightly report that runs once looks like an emergency; a 40 ms query that runs 90,000 times a day looks fine. In reality the report costs 30 seconds of waiting a day and the query costs 3,600.
Slowpoke multiplies duration by how often the thing actually happened, divides by the period genuinely observed rather than a fixed week, deduplicates so that one request seen by nginx and by OpenTelemetry counts once, and sorts. What comes out is a list of expensive things rather than slow ones, and that is the list you need to plan a sprint.
What an application SDK cannot see
AppSignal lives inside your application process, which is the right place for errors and for transaction traces, and the wrong place for a surprising share of real slowness: a PHP-FPM pool with four workers, a database server at 17% iowait, a Redis evicting its working set, a nightly schedule:run overlapping the backup, or the reporting service that shares the database and nobody instrumented.
Slowpoke's agent sits on the machine, not in the process. It reads access logs, the php-fpm slow log, MySQL and PostgreSQL statistics with real query plans, Redis, /proc, queued jobs and scheduled commands, and traces each connection back to the process that opened it. Then it says what it still cannot read, with the lines that would fix that.
Can you run both?
Yes, easily. Slowpoke never sits in the request path and emits nothing to any vendor, so it cannot inflate an AppSignal request count or interfere with its instrumentation. Keep AppSignal for errors and alerting; let Slowpoke own the priced backlog and the database work.
FAQ
Slowpoke and AppSignal, asked plainly
Is Slowpoke a free alternative to AppSignal?
Will running Slowpoke increase my AppSignal bill?
Does Slowpoke support Ruby and Elixir?
Which is lighter on my application?
Find out what you inherited
Give it fifteen minutes on one server and the first number is yours. Finding out costs nothing.