Small tools.
Each one solves a single specific problem an engineer might land on at 2am. Open source, free, no signup, runs in your browser. Hosted here as a place to put the small things that didn't deserve their own repo, but were useful enough to ship.
showing 10 of 11
Networking
5DNS race around the world
Type a domain. Watch four global DoH resolvers race to answer, plotted on a live 3D globe.
CIDR calculator (IPv4 + IPv6)
Type a CIDR. Get the network, broadcast, range, host count, and neighbour subnets.
DNS-over-HTTPS visualizer
Look up A, AAAA, MX, TXT, CNAME, NS, CAA records side-by-side via Cloudflare and Google DoH.
TLS cert inspector
Look up a domain's TLS chain. Issuer, expiry countdown, SANs, signature algorithm, validity.
Public-web latency race
Race the same HEAD request against major edge networks. Live bars, browser-side timing.
AI
4Multi-provider tokenizer + cost estimator
Paste a prompt. See token counts and per-call cost across Anthropic, OpenAI, and Google.
Cassette explorer
Drop a cuesheet YAML file. Browse interactions in the same UI that ships with the package.
Streaming SSE viewer
Paste an SSE response. See each frame decoded, with event names and JSON-pretty payloads.
Prompt diff viewer
Paste two prompts side by side. Get a semantic diff with role-aware highlighting.