Fehlo and Sentry compared.
Both collect errors from the same SDKs. They differ in where the data lives, how you are billed and what is included.
Sentry facts as of 21 October 2026, feature list as of 18 October 2026, with sources at the bottom. If you spot a mistake, write to hallo@fehlo.de and we will fix it.
Provider and data location
| Topic | Fehlo | Sentry |
|---|---|---|
| Provider | NeuralMedic GmbH, Ingolstadt, Germany | Functional Software, Inc., San Francisco |
| Errors, traces, logs | Germany (Hetzner, Nuremberg) | US (Iowa) or EU region (Frankfurt)1 |
| Accounts, settings, project metadata, DSN keys, audit logs | Germany | US, whatever region you choose1 |
| Changing region later | not applicable | not possible except with a new organisation1 |
| Transfer to the US | none for events, accounts and settings | EU-U.S. Data Privacy Framework, standard contractual clauses as fallback2 |
| Data processing agreement | DPA under Art. 28 GDPR, on request to hallo@fehlo.de | Data Processing Addendum, must be accepted actively2 |
| Running it yourself | not offered; a dedicated instance on the Dedicated plan, run by us | self-hosted under the Functional Source License, from 4 cores, 16 GB RAM and 16 GB swap4 |
Pricing
| Plan | Fehlo | Sentry |
|---|---|---|
| Free | Free: 5,000 events, 1 user | Developer: 5,000 errors, 1 user3 |
| Cheapest paid plan | Solo: €9 a month, 100,000 events, 3 users | Team: $29 a month or $26 billed yearly, 50,000 errors, unlimited users3 |
| Unlimited users | Team: €29 a month, 500,000 events | Team: $29 a month, 50,000 errors3 |
| Next tier | Agency: €79 a month, 2,000,000 events | Business: $89 a month or $80 billed yearly, 50,000 errors3 |
| What counts against the quota | events: errors only, failed Make and Zapier runs included; transactions and log lines have their own allowances, uploads their own storage; uptime checks and heartbeat pings don't count | separate quotas; every plan includes 5M spans, 50 replays, 5 GB of logs, 1 uptime monitor, 1 cron monitor3 |
| Performance | transactions a month: 100,000 on Free, 1M on Solo, 5M on Team, 20M on Agency; a transaction counts once, however many spans it contains | 5M spans on every plan, Developer included3 |
| Logs | log lines a month: 250,000 on Free, 2.5M on Solo, 10M on Team, 40M on Agency | 5 GB on every plan3; a log line is usually 0.2 to 1 KB, so 5 GB is roughly 5 to 25 million lines |
| Uptime and cron monitors | included in the plan: 20 on Free (every 5 minutes), 50 on Solo, 150 on Team, 500 on Agency (every minute); SSL and domain monitors unlimited | 1 uptime and 1 cron monitor included, each additional one billed per monitor and month3 |
| Above the quota | events: €0.15 per 1,000, tiered down to €0.08, only with your consent and up to your limit; transactions and log lines: not available, only that data pauses until the end of the billing month | errors on Team from $0.3625 per 1,000, tiered down to $0.156 |
| Retention | 30 days on every plan | 30 days (Developer), up to 90 days (Team, Business)3 |
| AI help with fixes | fix prompt for Cursor, Claude Code or Lovable, without variable values, included | Seer: $40 per active contributor per month6 |
| Currency | euros, net plus VAT | US dollars, excluding tax3 |
In Fehlo, events are errors only. Transactions and spans are different units, though. A transaction, such as a page load or a request, usually consists of several spans, so how far an allowance goes depends on how many spans your transactions have. tracesSampleRate sets the share of transactions that gets measured.
Features
| Feature | Fehlo | Sentry |
|---|---|---|
| Issues with stack trace, breadcrumbs, local variables, tags | yes | yes |
| Source maps, ProGuard, dSYM, PDB via sentry-cli | yes | yes |
| Performance: transactions with p50, p95, error rate | yes | yes |
| Trace waterfall per request | no | yes7 |
| Logs with search and live tail | yes | yes7 |
| Session replay | no (coming) | yes7 |
| Profiling, release health | no | yes7 |
| Uptime monitors | HTTP, ping, TCP, SSL certificate, domain, heartbeat | HTTP5 |
| Status pages for your customers | yes, on every plan with your logo, on your own domain from Team | not found5 |
| Alert channels | on every plan: email, Slack and other Slack-compatible webhooks, Microsoft Teams, Discord, Google Chat, ntfy, Zulip, Feishu | email, Slack, Microsoft Teams, Discord, PagerDuty, Opsgenie7 |
| GitHub: code links, commits, issues | yes | yes7 |
| Tickets in Jira, Linear | no (coming) | yes7 |
| GitLab | no | yes7 |
| Single sign-on | Dedicated plan | SAML from Business7 |
| MCP server for AI agents | yes | yes7 |
Which one fits
Sentry fits better if your team uses session replay, profiling, release health or deep GitHub, Jira and Slack integrations every day, if you need more than 30 days of history, or uptime checks from several regions.
Fehlo fits better if your customers or your data protection officer require a German provider with no transfer of data to the US, if you want to pay in euros, if you want errors, uptime and status pages in one product, or if you are an agency looking after many client projects separately.
How the switch works is on the Sentry alternative page.
Sources
- Sentry documentation, "Data Storage Location", docs.sentry.io/organization/data-storage-location, retrieved 21 October 2026.
- Sentry Data Processing Addendum, sentry.io/legal/dpa, retrieved 21 October 2026.
- Sentry pricing page, sentry.io/pricing, retrieved 21 October 2026. Prices in US dollars, excluding tax.
- Sentry developer documentation, "Self-Hosted Sentry", develop.sentry.dev/self-hosted, retrieved 21 October 2026.
- Sentry documentation, "Uptime Monitoring", docs.sentry.io/product/uptime-monitoring, and changelog, sentry.io/changelog, retrieved 21 October 2026. We found no customer-facing status pages there.
- Sentry documentation, "Pricing & Billing", docs.sentry.io/pricing, retrieved 21 October 2026.
- Sentry product documentation, docs.sentry.io/product, and integrations list, docs.sentry.io/organization/integrations, retrieved 18 October 2026.
Sentry is a trademark of Functional Software, Inc. Fehlo is not affiliated with Sentry.
Questions
Is Fehlo cheaper than Sentry?
For the same number of errors, usually yes: Fehlo Team costs €29 for 500,000 events, Sentry Team $29 for 50,000 errors (sentry.io/pricing, 21 October 2026). Both give logs their own allowance: Sentry includes 5 GB, Fehlo 250,000 log lines on Free and 10 million on Team; at 0.2 to 1 KB per line, 5 GB is roughly 5 to 25 million lines. For performance data, Sentry's free plan includes 5 million spans; at 10 spans per transaction that covers 500,000 transactions, while Fehlo Free includes 100,000. On Team, Sentry also includes 5 million spans and Fehlo 5 million transactions. Beyond the first one, Sentry bills uptime and cron monitors per monitor; in Fehlo they come with the plan.
Can I use Fehlo with my Sentry SDK?
Yes. You change the DSN; your code, SDK and sentry-cli stay. The guides show how for each framework.
Is Fehlo a fork of Sentry?
No. The engine is GlitchTip (MIT licence), which contains BSD-licensed code that Sentry published in the past. We have extended it with features, fixes and our own interface. Details under open source licences.