Observability tools with a free plan in 2026
Understand what a system is doing from its telemetry: metrics, logs, traces, profiles and errors. This list has 131 observability tools. Of these, 71 are open source, 131 have a free plan and 91 can be self-hosted. Checked by hand on 30 September 2026.
- 1
AgentOps
Observability for AI agents: records agent sessions with LLM calls, tool use and costs so you can replay and debug runs; SDK and app are open source.
- 2
Airbrake
Long-running error and performance monitoring service that groups exceptions, links them to deploys and alerts by email or chat. Error and performance quotas are billed separately.
- 3
Amazon Managed Service for Prometheus
Serverless, Prometheus-compatible metrics store on AWS: remote-write metrics from EKS or other clusters and query them with PromQL.
- 4
Apache SkyWalking
APM for distributed systems from the Apache Software Foundation: agents and service mesh probes collect traces, metrics and logs and draw service topology maps.
- 5
AppSignal
APM for Ruby, Elixir, Node.js, Python, PHP, Go and front-end JavaScript that combines performance, errors, logs, host metrics, uptime checks and cron check-ins.
- 6
Arize AX
Arize's hosted AI observability and evaluation platform for agents and ML models: tracing, online evals, monitors and dashboards.
- 7
Arize Phoenix
Source-available LLM tracing and evaluation tool built on OpenTelemetry and OpenInference; run it locally, in a notebook or on your servers to inspect traces and score outputs.
- 8
AWS Distro for OpenTelemetry
AWS-supported distribution of the OpenTelemetry Collector and SDKs, preconfigured to send traces and metrics to CloudWatch, X-Ray, Amazon Managed Prometheus and partner backends.
- 9
Axiom
Hosted event store for logs, traces and other event data, queried with the APL language, with dashboards and monitors. Integrates with Vercel, Cloudflare and OpenTelemetry.
- 10
Backtrace
Crash and error reporting from Sauce Labs for native apps, game engines, consoles and servers, including minidump and core dump processing.
- 11
Better Stack Telemetry
Better Stack's log, metric and trace store built on ClickHouse, queried with SQL or a live-tail view. Shares an account with Better Stack uptime and on-call.
- 12
Bindplane
Telemetry pipeline built on OpenTelemetry: manages fleets of collectors from one console and filters, samples and routes logs, metrics and traces to any backend. Cloud or self-hosted.
- 13
Boomerang
Open source JavaScript library, maintained by Akamai, that measures page load and user-perceived performance in real browsers and beacons the timings to a server you choose.
- 14
Braintrust
Evaluation and observability platform for AI products: logs production traces, runs evals and scorers, and offers a prompt playground and datasets.
- 15
Bugfender
Remote logging for mobile and web apps: the SDK sends device logs to the cloud so you can read what happened on a user's device, with crash reports and user feedback.
- 16
Bugsee
In-app bug and crash reporting for mobile apps that attaches a video of the user's last actions, network traffic and logs to every report.
- 17
Bugsink
Sentry-SDK-compatible error tracker built to self-host as a single container on modest hardware. Groups errors into issues and sends chat or webhook alerts.
- 18
BugSnag
SmartBear's error and crash monitoring for mobile, web and backend apps, known for stability scores per release. Adds performance spans.
- 19
BugSplat
Crash reporting for C++, .NET, games and desktop apps: collects minidumps and symbol files and shows the call stack at the moment of the crash.
- 20
Chronograf
InfluxData's web UI for InfluxDB 1.x: builds dashboards over InfluxQL queries and manages Kapacitor alert rules.
- 21
ClickStack
ClickHouse's open source observability stack built on HyperDX: logs, traces, metrics and session replays stored in ClickHouse and searched from one UI.
- 22
Cloudflare Web Analytics
Privacy-first, cookie-free site analytics from Cloudflare that also reports real-user Core Web Vitals per page; works on sites not proxied by Cloudflare too.
- 23
Confident AI
Evaluation and observability platform from the makers of the open source DeepEval library: LLM tracing, regression tests in CI, and red teaming.
- 24
Contentsquare
Digital experience analytics platform with session replay, heatmaps, journey analysis and error and speed analysis; Hotjar is now part of it.
- 25
Coroot
Open source observability that uses eBPF to build service maps and collect metrics, logs, traces and profiles without code changes, with root-cause hints.
- 26
Cortex
Horizontally scalable, multi-tenant long-term storage for Prometheus metrics; a CNCF project.
- 27
Cribl
Telemetry pipeline (Cribl Stream, Edge, Search and Lake) that filters, reshapes and routes logs between collectors and destinations such as Splunk or S3 to cut volume.
- 28
Datadog
SaaS monitoring platform covering infrastructure, APM, logs, RUM, synthetics, security and incident management, collected mostly through one agent.
- 29
DeadBro
APM for Ruby on Rails apps installed as a gem: request traces, slow SQL and N+1 query detection, and error tracking, priced by requests.
- 30
Dozzle
Small web UI that streams and searches live Docker container logs across hosts, with no log storage. Optional Dozzle Cloud adds grouped alerts and log analysis.
- 31
Edge Delta
Telemetry pipelines that process logs, metrics and traces at the edge before they reach a backend, now sold alongside AI agents for root-cause investigation.
- 32
Elastic Observability
Logs, metrics, APM traces and synthetics built on Elasticsearch and Kibana, run yourself or on Elastic Cloud.
- 33
Elastic Stack (ELK)
Elasticsearch, Logstash, Kibana and Beats: full-text indexing and search of logs with Kibana dashboards and alerting. Self-host the free distribution or buy Elastic Cloud.
- 34
Embrace
Mobile and web app monitoring built on OpenTelemetry: crashes, ANRs, network calls and full user session timelines for iOS, Android, React Native and Unity.
- 35
Errbit
Self-hosted Rails app that receives errors from Airbrake-compatible clients, groups them and emails or notifies your team.
- 36
Exceptionless
Open source .NET-first error, log and feature-usage reporting with a hosted service or free self-hosting. Groups events into stacks and notifies on new or regressed errors.
- 37
Firebase Crashlytics
Google's crash reporter for iOS, Android, Flutter and Unity apps. Groups crashes by root cause and highlights new or regressed issues; no cost on any Firebase plan.
- 38
Fluent Bit
Lightweight C log and metrics processor from the Fluentd project, common as the node-level agent in Kubernetes. Ships to Loki, Elasticsearch, cloud logging and OTLP.
- 39
Fluentd
CNCF graduated log collector that reads, parses, buffers and forwards logs to hundreds of outputs through a plugin system. Written in Ruby and C.
- 40
Fullstory
Digital experience analytics built on session replay: records web and mobile sessions, flags frustration signals and errors, and lets you search and segment users by behaviour.
- 41
Future AGI
Open source platform to trace, evaluate, simulate and guard LLM and agent apps, including an AI gateway.
- 42
Galileo
AI evaluation and observability platform with tracing, evaluation metrics and real-time guardrails for agents; hosted, VPC or on-prem.
- 43
GlitchTip
Open source error tracker that accepts events from Sentry SDKs, with simpler infrastructure than self-hosted Sentry. Also does basic uptime checks. Hosted or self-hosted.
- 44
Google Cloud Profiler
Google Cloud statistical profiler for Go, Java, Node.js and Python services that samples CPU and heap in production and shows flame graphs in the console. Google lists no charge for it.
- 45
gProfiler
Open source system-wide profiler from Intel (built by Granulate) that merges several language profilers into one flame graph per host; a local backend and UI are published separately.
- 46
Grafana
Open source dashboards and alerting over Prometheus, Loki, Elasticsearch, SQL databases and many other data sources.
- 47
Grafana Alloy
Grafana's OpenTelemetry Collector distribution with built-in Prometheus scraping and a pipeline configuration language; collects metrics, logs, traces and profiles. Replaces Grafana Agent.
- 48
Grafana Cloud
Grafana Labs' hosted stack: Grafana with managed Prometheus-compatible metrics, Loki logs, Tempo traces, profiles, synthetic checks and IRM.
- 49
Grafana Faro
Open source web SDK for frontend observability: captures page performance, Web Vitals, errors, logs and traces from browsers and sends them to Grafana Cloud or a self-run Alloy and Loki stack.
- 50
Grafana Loki
Log aggregation system that indexes only labels, not full log text, and stores chunks in object storage. Queried with LogQL from Grafana; hosted as part of Grafana Cloud.
- 51
Grafana Mimir
Horizontally scalable, multi-tenant long-term storage for Prometheus metrics from Grafana Labs, backed by object storage.
- 52
Grafana Pyroscope
Continuous profiling database that collects CPU, memory and other profiles from running applications so you can find hot code paths over time.
- 53
Grafana Tempo
Distributed tracing backend that stores traces cheaply in object storage and accepts OpenTelemetry, Jaeger and Zipkin data.
- 54
Graphite
Time-series metrics storage and graphing: Carbon receives metrics, Whisper stores them, and Graphite-web renders graphs and serves a query API.
- 55
Graylog
Centralised log collection with parsing pipelines, stream routing, search and alert conditions. Graylog Open is free to self-host; paid editions add security analytics and archiving.
- 56
Grepr
Pipeline that sits in front of Datadog, Splunk or New Relic, summarises repetitive logs and traces before they are indexed, and keeps raw data in S3 for backfill during incidents.
- 57
groundcover
Kubernetes observability that uses an eBPF sensor and runs in your own cloud account, covering logs, traces, metrics and APM without code changes.
- 58
Helicone
Open source LLM proxy and logging: point your provider base URL at it to record every request with cost, latency and user, plus caching and rate limits.
- 59
Honeybadger
Error tracking for Ruby, Elixir, PHP, Python and JavaScript apps, bundled with uptime checks, cron check-ins and log insights in one account.
- 60
Honeycomb
Observability built for high-cardinality event data: query traces and events by any field to work out why production behaves the way it does.
- 61
Honeycomb Refinery
Open source tail-based sampling proxy for traces: buffers whole traces and keeps errors, slow requests and a sample of the rest before forwarding to Honeycomb.
- 62
HoneyHive
Observability and evaluation platform for AI agents: OpenTelemetry-based tracing, automated and human evals, prompt versioning and production monitoring.
- 63
InfluxDB
Time-series database for metrics and events; InfluxDB 3 Core is open source, with Enterprise and managed cloud editions.
- 64
Inspector
Code-level monitoring for PHP apps (Laravel, Symfony, CodeIgniter, Drupal) that shows transactions, database queries and errors as they happen.
- 65
Jaeger
CNCF distributed tracing platform for collecting, storing and exploring request traces across microservices; version 2 is built on the OpenTelemetry Collector.
- 66
Laminar
Open source observability for AI agents: OpenTelemetry-based tracing, evaluations and analysis of agent runs, self-hostable or cloud.
- 67
Langfuse
Open source LLM engineering platform: traces LLM and agent calls, manages prompts, runs evaluations and tracks cost and latency. Self-host or use the cloud; acquired by ClickHouse in 2026.
- 68
LangSmith
LangChain's platform for tracing, evaluating and monitoring LLM apps and agents, usable with or without LangChain; also hosts agent deployments.
- 69
LangWatch
Open source LLMOps platform: traces LLM and agent runs, runs evaluations and agent simulations, and helps optimize prompts; cloud or self-managed.
- 70
Last9
Telemetry data platform for high-cardinality metrics, logs and traces, compatible with Prometheus and OpenTelemetry.
- 71
Latitude
Open source platform to trace, monitor and evaluate AI agents in production, with prompt management; self-host or use the hosted plans.
- 72
lnav
Terminal log file navigator that merges several log files into one timeline, highlights errors, and lets you query log lines with SQL. Runs locally, no server.
- 73
Logflare
Log ingestion and search backed by Google BigQuery, popular with Cloudflare Workers, Vercel and Elixir apps. Now part of Supabase and open source.
- 74
Loggly
SolarWinds hosted log management: ship logs over syslog or HTTP, search and filter them, and build charts and email alerts on the paid plans.
- 75
Lumigo
Troubleshooting for serverless and container apps with automatic distributed tracing that captures request and response payloads across AWS Lambda and other services.
- 76
ManageEngine Log360 Cloud
ManageEngine's cloud SIEM that collects logs from servers, network devices and cloud services for search, audit reports and compliance reporting. Has a Free edition.
- 77
Memfault
Device reliability platform for embedded and IoT fleets: remote crash and coredump collection, device metrics and over-the-air update management.
- 78
Microsoft Clarity
Free session recordings and heatmaps from Microsoft, with rage-click and dead-click detection and JavaScript error markers on recordings. No traffic caps.
- 79
Middleware
Full-stack observability SaaS covering infrastructure, APM, logs, RUM and synthetic checks, priced by data volume.
- 80
New Relic
SaaS observability platform for APM, infrastructure, logs, browser and mobile monitoring and errors, priced by data ingest and user type.
- 81
Nightingale
Open source alerting and dashboard platform that sits on Prometheus, VictoriaMetrics, Elasticsearch and other sources, with alert rules and notification routing.
- 82
NXLog
Log collection agent and platform strong on Windows event logs: collects, converts and forwards logs to SIEM and observability tools. A free Community Edition is also available.
- 83
Odigos
Uses eBPF to add OpenTelemetry tracing to applications on Kubernetes without code changes and sends the data to any backend.
- 84
OpenLIT
Open source, OpenTelemetry-native AI observability: SDK auto-instruments LLMs, vector databases and GPUs, with a self-hosted UI for traces, costs, evals and prompts.
- 85
OpenLLMetry
Open source OpenTelemetry instrumentations for LLM providers, vector databases and agent frameworks, by Traceloop; sends traces to any OTLP backend or the Traceloop platform.
- 86
OpenObserve
Single-binary store for logs, metrics and traces on object storage, with SQL search, dashboards and alerts. Self-host the open source build or use the pay-as-you-go cloud.
- 87
OpenReplay
Open source session replay with developer tools attached: console logs, network requests and performance data alongside each recording, plus co-browsing. Self-host free or use a managed instance.
- 88
OpenSearch
Apache-licensed fork of Elasticsearch and Kibana run under the Linux Foundation. Indexes and searches logs, with OpenSearch Dashboards, alerting and trace analytics plugins.
- 89
OpenTelemetry
CNCF project defining vendor-neutral APIs, SDKs, semantic conventions and the OTLP protocol for traces, metrics, logs and profiles, with auto-instrumentation for major languages.
- 90
OpenTelemetry Collector
Vendor-neutral agent and gateway that receives, processes and exports traces, metrics and logs to one or more backends.
- 91
OpenTelemetry eBPF Instrumentation (OBI)
Zero-code eBPF instrumentation that produces traces and RED metrics for HTTP, gRPC, database and messaging calls from Linux processes. Started as Grafana Beyla and was donated to OpenTelemetry.
- 92
OpenTelemetry eBPF Profiler
Whole-system eBPF profiling agent donated to OpenTelemetry by Elastic. Profiles native, JVM, Python, Ruby, PHP, Node.js and Go code without instrumentation and exports via OTLP.
- 93
Opik
Open source LLM and agent observability from Comet: tracing, test suites, evaluations and a prompt optimizer; self-host the same code as the cloud.
- 94
Parca
Open source continuous profiler: an eBPF agent samples CPU stacks from every process on a host with no code changes, and the server stores profiles for querying as flame graphs over time.
- 95
Parseable
Log and telemetry store written in Rust that keeps data as Parquet on object storage and queries it with SQL. Open source server, plus a hosted cloud and enterprise edition.
- 96
Perforator
Continuous profiler open sourced by Yandex for large fleets: deploys to Kubernetes, collects low-overhead eBPF profiles cluster-wide, and can feed profile-guided optimization builds.
- 97
Perses
CNCF open source dashboard tool with an open dashboard specification: Prometheus, Tempo and Loki panels, dashboards as code, and Kubernetes-native deployment.
- 98
Pinpoint
APM for large Java and PHP systems that traces transactions across services and draws a server map of their calls.
- 99
Pixie
Kubernetes observability that uses eBPF to capture service traffic, metrics and CPU profiles automatically; a CNCF sandbox project.
- 100
Portkey
AI gateway with an observability layer: one API for many model providers with routing, fallbacks and caching, and logs of each request with cost and latency. The gateway is open source.
- 101
PostHog
Open source product suite with session replay, product analytics, feature flags, error tracking and LLM analytics sharing one event store. Hosted with a monthly free allowance, or self-hosted.
- 102
Prometheus
CNCF metrics system that scrapes time series from exporters and apps, stores them locally, and evaluates PromQL alert rules that it sends to Alertmanager.
- 103
Quickwit
Rust search engine for logs and traces that indexes into object storage and searches there directly, with Elasticsearch-compatible and Jaeger APIs. The team joined Datadog in January 2025.
- 104
Request Metrics
Real user monitoring focused on Core Web Vitals and page speed for websites, with lab tests, SEO tracking and email alerts when performance slips.
- 105
Respan
LLM gateway, logging and evaluation platform (formerly Keywords AI): routes calls to many models through one API and records traces, cost and scores.
- 106
Rollbar
Error monitoring that groups exceptions into items, ties them to deploys and versions, and alerts through Slack, PagerDuty and others. Includes session replay.
- 107
rrweb
Open source library that records DOM changes in the browser and replays them as a session video; the recording engine inside many session replay products.
- 108
rsyslog
Default syslog daemon on many Linux distributions; also a high-throughput log pipeline that parses, filters and forwards logs to Elasticsearch, Kafka, files or remote syslog.
- 109
Scout APM
APM for Ruby, Python, PHP and Elixir apps that points to slow endpoints, N+1 queries and memory bloat, with error and log monitoring included.
- 110
Sematext
Hosted infrastructure monitoring, log management, synthetic checks and real user monitoring, with a plan chosen per app.
- 111
Sentry
Captures exceptions and crashes from web, mobile and backend SDKs, groups them into issues with stack traces and releases, and alerts owners. Adds tracing, replays and logs.
- 112
Seq
Self-hosted server for structured logs and traces, popular in .NET shops via Serilog. Search with a SQL-like syntax, build dashboards and send alerts.
- 113
SigNoz
Open source, OpenTelemetry-native APM with traces, metrics and logs stored in ClickHouse, self-hosted or as SigNoz Cloud.
- 114
Site24x7
Zoho's monitoring suite for websites, servers, networks, applications and cloud, with synthetic transactions and RUM; plain uptime checks have a free plan.
- 115
Skylight
Performance profiler for Ruby on Rails apps that aggregates request traces into per-endpoint breakdowns; free for open source apps.
- 116
Smartlook
Session recording, heatmaps and funnels for web and mobile apps, owned by Cisco. Being wound down, with its features moving into Splunk Observability Cloud.
- 117
Smashing
Ruby (Sinatra) framework for team wallboard dashboards built from widgets that pull data from scripts and APIs; community fork of Shopify's Dashing.
- 118
Splunk
Log indexing and search platform (Splunk Enterprise, self-hosted, or Splunk Cloud) with the SPL query language, dashboards and alerting. Widely used for security and IT operations.
- 119
Superlog
Open source OpenTelemetry observability for traces, logs and metrics, with AI agents that investigate incidents; self-hostable or hosted.
- 120
syslog-ng
Long-running open source log collector and forwarder: receives syslog, files and journald, parses and filters messages, and sends them to files, databases, Kafka or SIEMs. Commercial editions exist.
- 121
Telegraf
InfluxData's plugin-based agent that collects metrics and events from systems, services and APIs and writes them to InfluxDB, Prometheus and many other outputs.
- 122
telemetry.dev
Observability for AI and LLM apps on OpenTelemetry: traces model and tool calls with tokens, cost, latency and errors; send OTLP over HTTP or use the TypeScript SDKs.
- 123
Tenzir
Open source pipeline engine for security and log data: nodes collect, parse, normalise and route events with a pipeline language, managed from a hosted or self-run platform.
- 124
Thanos
Adds a global query view, high availability and long-term object-storage retention to existing Prometheus servers; a CNCF project.
- 125
Uptrace
OpenTelemetry APM that stores traces, metrics and logs in ClickHouse, available self-hosted or as a cloud service priced per GB.
- 126
Vector
Rust observability pipeline from Datadog that collects, transforms and routes logs and metrics between sources and sinks, run as agent or aggregator.
- 127
VictoriaLogs
Log database from the VictoriaMetrics team, run as a single binary or cluster, queried with LogsQL and viewable in Grafana. Accepts Loki, Elasticsearch and OTLP ingestion.
- 128
VictoriaMetrics
Prometheus-compatible time-series database and monitoring stack in single-node and cluster versions, with enterprise and managed cloud editions.
- 129
W&B Weave
Weights & Biases toolkit for tracing LLM calls, running evaluations with custom scorers and comparing model and prompt versions.
- 130
Zipkin
Distributed tracing system that collects timing data from instrumented services and shows where latency builds up across them.
- 131
zymtrace
Self-hosted, cluster-wide profiler for AI training and inference fleets: continuous whole-system CPU profiling plus GPU and accelerator profiling for CUDA, ROCm and other chips.
Side by side
| Tool | Pricing | Free plan | Open source | Self-hosted |
|---|---|---|---|---|
| AgentOps | Free plan | Yes | Yes | Yes |
| Airbrake | Free plan | Yes | No | No |
| Amazon Managed Service for Prometheus | Free plan | 40M samples ingested, 10 GB stored (AWS Free Tier) | No | No |
| Apache SkyWalking | Free | Yes | Yes | Yes |
| AppSignal | Free plan | 30K requests, 1 GB logs, 5-day retention | No | No |
| Arize AX | Free plan | 25k spans/mo, 1 GB ingest, 15-day retention | No | No |
| Arize Phoenix | Free | Yes | No | Yes |
| AWS Distro for OpenTelemetry | Free | Yes | Yes | Yes |
| Axiom | Free plan | 500 GB/mo ingest, 25 GB storage, 30-day retention | No | No |
| Backtrace | Free plan | 25K errors/month, 1 month retention, 10 GB | No | Yes |
| Better Stack Telemetry | Free plan | 3 GB logs retained 3 days | No | No |
| Bindplane | Free plan | 10 collectors, 100 GB/day, 1 project | No | Yes |
| Boomerang | Free | Yes | Yes | Yes |
| Braintrust | Free plan | 1 GB processed data, 10k scores, 14-day retention | No | Yes |
| Bugfender | Free plan | 100K log lines/day, 24-hour retention | No | No |
| Bugsee | Free plan | Lite: 5 devices/month, 3-day retention | No | No |
| Bugsink | Free plan | Hosted: 15K events/month; self-hosted free | No | Yes |
| BugSnag | Free plan | 7.5K events/month, 1 user, 7-day retention | No | No |
| BugSplat | Free plan | 15,000 crashes/month, 3 users, 1-month retention | No | No |
| Chronograf | Free | Yes | Yes | Yes |
| ClickStack | Free plan | Yes | Yes | Yes |
| Cloudflare Web Analytics | Free | Yes | No | No |
| Confident AI | Free plan | 2 seats, 1 project, 1 GB-month of trace spans | No | Yes |
| Contentsquare | Free plan | Yes | No | No |
| Coroot | Free plan | Yes | Yes | Yes |
| Cortex | Free | Yes | Yes | Yes |
| Cribl | Free plan | Up to 1 TB/day | No | Yes |
| Datadog | Free plan | 5 hosts, 1-day metric retention | No | No |
| DeadBro | Free plan | 50k requests/mo, 1 app | No | No |
| Dozzle | Free plan | Yes | Yes | Yes |
| Edge Delta | Free plan | Yes | No | No |
| Elastic Observability | Free plan | Yes | Yes | Yes |
| Elastic Stack (ELK) | Free plan | Yes | Yes | Yes |
| Embrace | Free plan | 1M sessions/year, 5 users | No | No |
| Errbit | Free | Yes | Yes | Yes |
| Exceptionless | Free plan | 3,000 events/month, 1 user, 3-day retention | Yes | Yes |
| Firebase Crashlytics | Free | Yes | No | No |
| Fluent Bit | Free | Yes | Yes | Yes |
| Fluentd | Free | Yes | Yes | Yes |
| Fullstory | Free plan | 30,000 sessions/mo, 12-month retention | No | No |
| Future AGI | Free plan | Yes | Yes | Yes |
| Galileo | Free plan | Yes | No | Yes |
| GlitchTip | Free plan | 1,000 events/month | Yes | Yes |
| Google Cloud Profiler | Free | Yes | No | No |
| gProfiler | Free | Yes | Yes | Yes |
| Grafana | Free plan | Yes | Yes | Yes |
| Grafana Alloy | Free | Yes | Yes | Yes |
| Grafana Cloud | Free plan | 10k metric series, 50 GB logs, 14-day retention | No | No |
| Grafana Faro | Free plan | Yes | Yes | Yes |
| Grafana Loki | Free plan | Grafana Cloud: 50 GB logs/month, 14-day retention | Yes | Yes |
| Grafana Mimir | Free plan | Yes | Yes | Yes |
| Grafana Pyroscope | Free plan | Yes | Yes | Yes |
| Grafana Tempo | Free plan | Yes | Yes | Yes |
| Graphite | Free | Yes | Yes | Yes |
| Graylog | Free plan | Yes | No | Yes |
| Grepr | Free plan | Up to 4 TB/mo logs, 2 pipelines | No | No |
| groundcover | Free plan | Yes | No | Yes |
| Helicone | Free plan | 10,000 requests, 1 GB storage, 1 seat | Yes | Yes |
| Honeybadger | Free plan | Developer: 5,000 errors/month | No | No |
| Honeycomb | Free plan | 20M events/mo | No | No |
| Honeycomb Refinery | Free | Yes | Yes | Yes |
| HoneyHive | Free plan | 10,000 events/mo, 5 users, 30-day retention | No | Yes |
| InfluxDB | Free plan | Yes | Yes | Yes |
| Inspector | Free plan | 30K transactions/mo, 3 team members | No | No |
| Jaeger | Free | Yes | Yes | Yes |
| Laminar | Free plan | 1 GB data, 7-day retention, 1 seat | Yes | Yes |
| Langfuse | Free plan | 50k units/mo, 30 days data access, 2 users | Yes | Yes |
| LangSmith | Free plan | 5k base traces/mo, 1 seat | No | Yes |
| LangWatch | Free plan | 50k events/mo, 14-day data access, 2 users | Yes | Yes |
| Last9 | Free plan | Yes | No | No |
| Latitude | Free plan | 20K credits/mo, 30-day retention | Yes | Yes |
| lnav | Free | Yes | Yes | Yes |
| Logflare | Free plan | 12.96M events/month, 3-day retention | Yes | Yes |
| Loggly | Free plan | Lite: 200 MB/day, 7-day retention | No | No |
| Lumigo | Free plan | 150k traces, 5 GB logs/mo | No | No |
| ManageEngine Log360 Cloud | Free plan | Yes | No | No |
| Memfault | Free plan | Nordic devs: up to 10 development devices | No | No |
| Microsoft Clarity | Free | Yes | No | No |
| Middleware | Free plan | 100 GB data, 14-day retention | No | No |
| New Relic | Free plan | 100 GB ingest/mo, 1 full platform user | No | No |
| Nightingale | Free plan | Yes | Yes | Yes |
| NXLog | Free plan | Yes | No | Yes |
| Odigos | Free plan | Yes | Yes | Yes |
| OpenLIT | Free | Yes | Yes | Yes |
| OpenLLMetry | Free plan | Traceloop: 50K spans/mo, 5 seats, 24h retention | Yes | Yes |
| OpenObserve | Free plan | Yes | Yes | Yes |
| OpenReplay | Free plan | Yes | Yes | Yes |
| OpenSearch | Free | Yes | Yes | Yes |
| OpenTelemetry | Free | Yes | Yes | Yes |
| OpenTelemetry Collector | Free | Yes | Yes | Yes |
| OpenTelemetry eBPF Instrumentation (OBI) | Free | Yes | Yes | Yes |
| OpenTelemetry eBPF Profiler | Free | Yes | Yes | Yes |
| Opik | Free plan | 25k spans/mo, 10 members, 60-day retention | Yes | Yes |
| Parca | Free | Yes | Yes | Yes |
| Parseable | Free plan | Yes | Yes | Yes |
| Perforator | Free | Yes | Yes | Yes |
| Perses | Free | Yes | Yes | Yes |
| Pinpoint | Free | Yes | Yes | Yes |
| Pixie | Free | Yes | Yes | Yes |
| Portkey | Free plan | 10k logs/mo, 3-day log retention | No | Yes |
| PostHog | Free plan | 5K session recordings and 1M events per month | Yes | Yes |
| Prometheus | Free | Yes | Yes | Yes |
| Quickwit | Free | Yes | Yes | Yes |
| Request Metrics | Free plan | 1 user, Core Web Vitals monitoring, email alerts | No | No |
| Respan | Free plan | 100k logs, 1k scores | No | Yes |
| Rollbar | Free plan | 5K occurrences + 1K sessions/month | No | No |
| rrweb | Free | Yes | Yes | Yes |
| rsyslog | Free | Yes | Yes | Yes |
| Scout APM | Free plan | 300K transactions, 5k errors, 1 GB logs | No | No |
| Sematext | Free plan | Yes | No | No |
| Sentry | Free plan | Developer: 5K errors/month, 1 user | No | Yes |
| Seq | Free plan | Individual: 1 user, 50 GB storage | No | Yes |
| SigNoz | Free plan | Yes | Yes | Yes |
| Site24x7 | Free plan | Uptime checks for 50 resources, email alerts | No | No |
| Skylight | Free plan | 100,000 traces/mo | No | No |
| Smartlook | Free plan | Yes | No | No |
| Smashing | Free | Yes | Yes | Yes |
| Splunk | Free plan | Splunk Free: 500 MB/day, one instance, no alerting | No | Yes |
| Superlog | Free plan | Yes | Yes | Yes |
| syslog-ng | Free plan | Yes | Yes | Yes |
| Telegraf | Free | Yes | Yes | Yes |
| telemetry.dev | Free plan | 30k ingestion units/mo, 14-day retention | No | No |
| Tenzir | Free plan | Community edition: 1 TB/day ingress | Yes | Yes |
| Thanos | Free | Yes | Yes | Yes |
| Uptrace | Free plan | 50 GB/mo | Yes | Yes |
| Vector | Free | Yes | Yes | Yes |
| VictoriaLogs | Free plan | Yes | Yes | Yes |
| VictoriaMetrics | Free plan | Yes | Yes | Yes |
| W&B Weave | Free plan | Yes | No | Yes |
| Zipkin | Free | Yes | Yes | Yes |
| zymtrace | Free plan | CPU profiling on up to 5 machines | No | Yes |
Plans and prices change; check each tool's own site before you decide.