DevOps is the category where small mistakes get expensive: a wrong subnet mask in a VPC, a checksum that does not match the release artifact, a base64 blob in a Kubernetes secret you cannot read. The platforms above are the infrastructure layer — containers, orchestration, pipelines and monitoring.

The DevToolBox utilities below cover the arithmetic and the decoding that surrounds all of it. They run entirely offline in the browser, which matters more here than anywhere else: the thing you are usually debugging is the network.

🧰 Free DevToolBox Tools

Client-side and free — nothing you paste leaves your browser:

CIDR / Subnet Calculator — Plan VPC and subnet ranges; returns network, broadcast, mask and usable host range for IPv4 and IPv6.
Hash Generator — Verify release artifacts with MD5, SHA-1, SHA-256, SHA-512, CRC32 and HMAC.
Base64 Encoder/Decoder — Decode Kubernetes secrets, Docker config files and CI variables.
Base64 Decoder — Decode Base64 back to readable text or binary.
JWT Debugger — Inspect the short-lived tokens your CI provider issues for OIDC cloud deployments.
JSON Formatter — Read pipeline definitions and Terraform state output.
Diff Checker — Compare two versions of a CI config to find the change that broke the build.
Timestamp Converter — Decode the epoch timestamps in logs and monitoring output.
UUID Generator — Generate identifiers for resource naming in test environments.

❓ Frequently Asked Questions

How do I work out how many hosts a subnet holds?

Enter the CIDR block, for example 10.0.0.0/24, into the CIDR calculator. It returns the network address, the broadcast address, the subnet mask and the usable host range for both IPv4 and IPv6 notation.

Why bother verifying a checksum?

A matching hash is evidence that the artifact you downloaded is byte-for-byte the one that was published. It catches truncated downloads and tampered mirrors — cheap to check, expensive to skip.

Is a JWT issued by a CI pipeline different from a normal JWT?

No, it is the same format. OIDC-based CI integrations issue short-lived JWTs so a pipeline can assume a cloud role without storing a long-lived secret key. The debugger shows you the claims, the issuer and the expiry.

Can I decode a Kubernetes Secret without a cluster?

Yes. Kubernetes stores Secret values as Base64, so decoding the value in a Base64 tool gives you the plaintext — no kubectl and no cluster access required. Treat the result as secret material.