Stop guessing which one. Put them side by side.

The grid says what these tools are. This says what builders did about it — one decision per person, changeable whenever you change your mind.

# Tool comparison — Checkly vs Highlight.io vs Axiom

Source: Kbaise, a directory of tools that work with Lovable projects.
Pick one and tell me why before writing any integration code.

## Checkly (checkly)
- URL: https://www.checklyhq.com
- Category: Monitoring & error tracking
- Cost: mixed — Free Hobby: 10K API and 1K browser check runs/mo, 7-day raw retention. Starter $24/mo. Team $64/mo ($51.20 annual) with 100K API and 12K browser runs.
- What it is: Synthetic monitoring defined as code: you write real Playwright scripts and API checks, keep them in the repo beside your app, and Checkly runs them on a schedule from global locations. Failures produce screenshots, traces and alerts. Configuration lives in a TypeScript file managed by the Checkly CLI.
- Why builders pick it: It catches the failures a plain uptime ping misses, like checkout still returning 200 while the button no longer works, and if you already write Playwright tests the monitors are nearly free to author.
- Trap: Browser checks are the ones you actually want and they burn quota far faster than API checks, with only 1K per month free. Free raw result retention is 7 days, and there is no self-hosted option.
- Wiring: npm create checkly@latest
- Full dossier: /api/public/tools/checkly

## Highlight.io (highlight-io)
- URL: https://www.highlight.io
- Category: Monitoring & error tracking
- Cost: free — Self-hosting is free under Apache 2.0. The hosted cloud ended 28 February 2026 and existing users were migrated to LaunchDarkly Observability.
- What it is: An open-source full-stack monitoring app combining session replay, error monitoring, logging and OpenTelemetry tracing in one self-hostable Docker stack. LaunchDarkly acquired it and folded the features into LaunchDarkly Observability. The GitHub repo remains public and actively committed to, but the hosted app.highlight.io service has shut down.
- Why builders pick it: It is now purely a self-host play: if you want replay plus errors plus traces on your own hardware with no per-event bill, this is one of very few Apache-2.0 options.
- Trap: Do not plan around the cloud product. It ended on 28 February 2026 and SDK snippets had to be repointed at LaunchDarkly before 1 March 2026. Self-hosting means operating ClickHouse, Kafka and Postgres yourself.
- Wiring: git clone https://github.com/highlight/highlight && docker compose up
- Full dossier: /api/public/tools/highlight-io

## Axiom (axiom)
- URL: https://axiom.co
- Category: Monitoring & error tracking
- Cost: mixed — Free Personal: 500GB ingest/mo, 25GB storage, 30-day retention, 10 GB-hours query. Axiom Cloud $25/mo platform fee including 1TB ingest, 100GB storage and 100 GB-hours.
- What it is: A serverless log and event store built on object storage and queried with the APL language, with dashboards, monitors and native OpenTelemetry ingest. The permanently free Personal plan allows 500GB of ingest per month, which is enormous for a solo project. Cloud-only, no self-hosted build.
- Why builders pick it: 500GB a month free is more log volume than a side project will ever generate, and the Vercel and Cloudflare integrations mean you can ship logs without writing a shipper.
- Trap: Free retention is fixed at 30 days and query compute is capped at 10 GB-hours per month, so busy dashboards hit that ceiling long before ingest becomes the constraint. No self-hosting option exists.
- Wiring: npm i @axiomhq/js
- Full dossier: /api/public/tools/axiom

## Quick read

- Free with no card: Highlight.io.

## Rules
1. Prefer the free tier when no budget was stated, and say what the ceiling is.
2. Read the full dossier before integrating.
3. Fetch /api/public/models before writing any AI model ID.

Agents can fetch the same thing: GET /api/public/compare?slugs=checkly,highlight-io,axiom