Free Reliability Tools

18 browser tools for SLA math, downtime dollars, incident docs, status pages, and quick smoke checks. No signup. Built for SREs, founders, and ops teams.

What this suite is (and is not)

TechImpact.online publishes 18 free reliability tools in one suite — no signup, no fake “Start Free Trial,” no vaporware Pro tier. Calculators and generators run entirely in your browser. Checkers call a simple API from our server when you click; they are single-location smoke tests, not replacement products for multi-region monitoring.

We are not trying to clone every feature of Site24x7 or Datadog. The suite follows two deliberate lanes: Hyperping-style operational utilities (post-mortems, cron, status pages, uptime/SSL/DNS checks) and our reliability-in-money wedge (SLA math, downtime dollars, error budgets, RTO/RPO, vendor claim packs). Every outage should be able to answer “what did it cost?” and “what SLA or credit lesson?” — not just “was ping green?”

Money & planning vs generators vs smoke checks

Money calculators turn uptime promises and outage minutes into numbers leadership understands: allowed downtime, error budget burn, revenue loss estimates, ROI of redundancy spend. Start in the Reliability Money Toolkit if that is your job.

Generators produce documents and assets: Markdown post-mortems, SLA claim text, cron strings, downloadable status HTML. They save formatting time during incidents — they do not detect failures automatically.

Smoke checkers answer narrow questions from outside your network: is this URL up, is TLS expiring, what do DNS records show, does /health return 200, is origin TTFB sane? Use them after deploys or during triage; schedule real monitoring separately.

Which tool first? — decision guide

Pick the row that matches your situation:

When to use the full catalog vs the Money Toolkit hub

The Reliability Money Toolkit is the curated path for SLA and downtime math with guides and shareable scenario URLs. This page is the complete catalog including generators and checkers. Bookmark both: Toolkit for recurring finance/SRE workflows; Free Tools when you need a generator or smoke check in one click.

All tools are free today. We do not sell your data or require accounts. Checkers are intentionally limited — we say so on every checker page because false confidence hurts more than honest scope.

Tool count and maintenance

We ship 18 tools today — calculators (8), generators/document tools (6), smoke checkers (5). Each page includes methodology, worked examples, and FAQ so you are not landing on a bare widget. We add tools when they fit the money + ops wedge; we do not clone entire enterprise monitoring suites.

Audience-specific starting paths

Founders / GM: Downtime Cost + Reliability ROI + one status page URL live before next launch.
SRE / platform: Error Budget + Allowed Downtime + smoke checkers in deploy runbook.
Finance / procurement: SLA Penalty Calculator + Claim Pack + calendar month reference tables.
Support / CS: Status page tools + link to official URL in macros; escalate with downtime minutes from Allowed Downtime when SLA promises exist.
Developers: Cron generator, REST API checker, DNS tool — keep bookmarks for triage after deploy.

None of these paths require payment or signup today. When we ship optional paid features in the future, core calculators will stay free — we will label pricing honestly on the site, not hide it behind trial CTAs.

Internal linking map (how tools connect)

Money calculators share math with reference guides. Generators link forward to post-mortems and claim packs after incidents. Checkers link backward to DNS and SSL when triaging “site down” reports. The Toolkit hub is the recommended entry for finance; this catalog is the entry for ops engineers bookmarking one bookmark per tool type.

Glossary (quick)

SLA — customer contract uptime. SLO — internal target, often stricter. Error budget — allowed failure before SLO miss. Smoke test — single external check, not monitoring. Post-mortem — blameless incident write-up. Claim pack — structured vendor credit request. Tools map to each term above.

Money & planning calculators

Turn uptime promises and outage minutes into budgets your team can debate. See also the Reliability Money Toolkit for curated paths.

SLA Penalty Calculator

Estimate tiered service credits when actual uptime falls below a promised percentage.

Open tool

Website Downtime Cost Calculator

Model revenue loss, refunds, conversion drop, and idle staff cost from an outage duration.

Open tool

RTO / RPO Impact Calculator

Compare recovery time and data-loss windows against business impact.

Open tool

Allowed Downtime Calculator

Convert SLA uptime % into allowed minutes — or reverse downtime into achieved uptime.

Open tool

Cost of Nines Calculator

See what each extra nine costs in minutes and compare investment vs risk.

Open tool

Error Budget Calculator

SLO target + period → error budget minutes; track burn % when you log incidents.

Open tool

Reliability ROI Calculator

Compare reliability investment cost against avoided downtime dollars.

Open tool

Generators & document tools

Produce claim packs, post-mortems, cron schedules, and status pages you can copy or download.

SLA Credit Claim Pack Generator

Vendor, period, promised %, downtime, and evidence notes → structured claim text.

Open tool

Post-Mortem Generator

Fill incident fields → Markdown post-mortem with timeline, root cause, and actions.

Open tool

Cron Expression Generator

Build or parse cron schedules with plain-English explanation and presets.

Open tool

Status Page Builder

Live preview + download a standalone HTML status page for your services.

Open tool

Status Page Templates

Minimal, dark ops, customer-friendly, and multi-service starter templates.

Browse templates

Free Status Page Download

Customize branding and download a ready-to-host static status.html — no backend.

Open tool

Smoke-test checkers

Quick checks from our server. Not multi-region monitoring — honest limits, useful for spot checks.

Website Availability Checker

HTTP status, ok/fail, and latency in milliseconds for any public URL.

Open tool

SSL Certificate Checker

Expiry date, days left, and issuer for a hostname.

Open tool

REST API Checker

GET or POST an endpoint and compare the status code to your expectation.

Open tool

DNS Analysis Tool

Look up A, AAAA, CNAME, MX, NS, and TXT records for a domain.

Open tool

Webpage Speed Smoke Test

TTFB and total load time — a lightweight smoke test, not full Lighthouse.

Open tool

How to use this suite over time

Reliability tooling fails when it is only bookmarked during disasters. A practical rhythm:

  1. Baseline quarterly: Run Allowed Downtime and Error Budget for your published SLO. Save screenshots or shareable URLs.
  2. Before major releases: Smoke-check staging/production health URLs, SSL expiry, and critical DNS records.
  3. After incidents: Downtime Cost → Post-Mortem → optional Claim Pack. Link numbers in the post-mortem impact section.
  4. During budget season: Reliability ROI and Cost of Nines for investment conversations — use low/mid/high inputs.
  5. Before you need it: Publish a static status page URL even if updates are manual — see Status Page Builder.

Worked scenario — vendor outage afternoon

14:00 — Cloud provider incident affects your API. Status page updated manually.

15:30 — Service restored. Downtime Cost: 90 min × $6k/hr peak ≈ $9k impact range.

16:00 — Error Budget: 90 min burn on 99.9% monthly SLO → over budget.

Next day — Post-Mortem published; Claim Pack emailed to vendor with UTC evidence.

What we deliberately do not offer (yet)

  • Hosted uptime monitoring with multi-region probes and paging.
  • Paid Pro saves, team workspaces, or PDF export gates.
  • Embeddable widgets or white-label API — link to tools instead.

Guides live under Guides and link back to tools. Questions or broken checks: Contact.

Frequently Asked Questions

Are TechImpact free tools really free?

Yes. Calculators and generators run in your browser with no account. Checkers use a simple server endpoint from one location — still no signup.

Which tool should I use first after an outage?

Website Downtime Cost, then Error Budget or Allowed Downtime, then Post-Mortem. Add SLA Credit Claim Pack if a vendor credit may apply.

Do the checkers replace full monitoring?

No. They are single-location smoke tests — useful for spot checks, not SLA proof or on-call alerting.

What makes TechImpact different from generic free tool sites?

We combine Hyperping-style generators and checkers with a reliability-in-money wedge: SLA math, downtime dollars, RTO/RPO, error budgets, and claim packs in one suite.

Where is the curated money-focused hub?

See the Reliability Money Toolkit for paths through SLA, downtime cost, RTO/RPO, and nines calculators with guides.

Is there a Pro tier or free trial?

No paid Pro or trial is offered today. Everything on this page is free in the browser without signup.

Which tool for vendor SLA credit vs customer SLA?

Vendor credit: SLA Penalty Calculator plus Claim Pack Generator. Customer SLA math: Allowed Downtime, Error Budget, and uptime reference guides.

Can I embed these tools in my site?

Link to tool pages directly. There is no embed widget product today.