Free Tools

Free DevOps Tools

13 small, focused tools for the questions engineers look up every week: when does this cron run, how many IPs are in this subnet, is it 512Mi or 512M, what does 99.95% actually allow, why is the CI bill this high. Everything runs in your browser: no signup, and nothing you paste is sent anywhere.

13 tools
6 categories
4 new
Your input never leaves the browser

Most used

Kubernetes Resource CalculatorTurn observed CPU and memory usage into starting-point requests and limits, with QoS class and cluster-wide totals.Open tool →Cron Expression GeneratorBuild or paste a cron schedule, read it in plain English and see the next run times, for crontab, Kubernetes CronJobs and GitHub Actions.Open tool →CIDR & Subnet CalculatorNetwork, broadcast, mask and usable hosts for any IPv4 CIDR, with AWS's five reserved addresses, VPC subnet splitting and an overlap check.Open tool →

All tools

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Kubernetes & containers

Kubernetes Resource CalculatorTurn observed CPU and memory usage into starting-point requests and limits, with QoS class and cluster-wide totals.docker run → ComposePaste a docker run command and get a compose.yaml service with ports, environment, volumes, restart policy and networks.YAML ↔ JSON ConverterNewConvert YAML to JSON and JSON to YAML in your browser, with line-numbered errors, multi-document support and output that's safe for kubectl.K8s CPU & Memory UnitsNewConvert Kubernetes quantities: millicores to cores, Mi and Gi to M, G and bytes, and catch the 500M-instead-of-500m and Mi-vs-M mistakes.

CI/CD

Cron Expression GeneratorBuild or paste a cron schedule, read it in plain English and see the next run times, for crontab, Kubernetes CronJobs and GitHub Actions.GitHub Actions Cost CalculatorEstimate your monthly GitHub Actions bill from runs, job duration and runner type, after your plan's included usage.

Cloud & cost

NAT Gateway Cost CalculatorEstimate NAT gateway hourly and data-processing charges, and how much S3 and DynamoDB gateway endpoints would save.

Networking & Linux

CIDR & Subnet CalculatorNetwork, broadcast, mask and usable hosts for any IPv4 CIDR, with AWS's five reserved addresses, VPC subnet splitting and an overlap check.Chmod CalculatorConvert between checkboxes, octal (755) and symbolic (rwxr-xr-x) Linux permissions, including setuid, setgid and the sticky bit.

SRE & reliability

Uptime & SLA CalculatorHow much downtime 99.9% or 99.99% allows per day, month and year, your remaining error budget, and burn-rate alert thresholds.Unix Timestamp ConverterNewConvert Unix epoch seconds, milliseconds, microseconds or nanoseconds to UTC and local time, and any date back to a timestamp.

Security

JWT DecoderDecode a JSON Web Token's header and payload in your browser, with readable exp, iat and nbf times and warnings for risky tokens.K8s Secret & Base64NewBuild a Kubernetes Secret manifest from key/value pairs, or base64-encode and decode values, without sending anything to a server.

How these tools work

Runs in your browser

No request leaves the page with your input. Paste tokens, manifests and IPs without worrying about where they end up.

No signup, no limits

Open a tool and use it. No account, no email gate, no daily quota.

Written by practitioners

Each tool comes with the explainer and FAQ we wished we had: the gotchas, the defaults and when the answer changes.

Questions people ask

Are these DevOps tools really free?

Yes. Every tool is free with no signup, no usage limit and no paywalled "pro" mode. The site is funded by ads and clearly labeled sponsors.

Is it safe to paste secrets, tokens or configs into these tools?

The tools run entirely in your browser. What you paste into the JWT decoder, Secret generator or YAML converter is never sent to a server or logged. Even so, treat production credentials as compromised once they've been copied around, and rotate them if in doubt.

How accurate are the cost calculators?

The GitHub Actions and NAT gateway calculators use the providers' published list prices, re-checked periodically, and say which region and rates they assume. They estimate list-price spend; discounts, credits and committed-use pricing will lower your real bill.

Can I suggest a new tool?

Yes. Most of these tools exist because readers asked for them. Send the idea through the about page and describe the question you keep looking up.

Request a tool

Missing the calculator you look up every week? Tell us what question it should answer and we'll consider it for the next batch. For quick reference there's also the DevOps troubleshooting cheat sheet.

Suggest a tool

Sponsor a tool

Each tool page can carry one clearly labeled sponsor, seen by engineers in the middle of the exact task your product helps with: CI cost, cloud networking, Kubernetes, reliability or secrets.

Sponsorship options