HIOS · Workbench
Local tools for validating, generating, and testing.
A clear workbench for payloads, audio, networking, and technical debugging. Runs in the browser with speed and privacy in mind.
- Local-first
- Open source
- Built for real work
The tools
33 tools · Everything runs in your browser. Pick one, or roll the dice.
Tone GeneratorConfigurable oscillator for testing speakers, DACs, filters and audio signal chains.Local onlyOpen toolGuitar TunerLocal chromatic tuner with pitch detection, nearest note and cents offset.Local onlyOpen toolSpectrum AnalyzerRealtime microphone FFT to inspect frequency energy from the browser.Local onlyOpen toolMetronomeConfigurable musical click with tempo, beats and subdivisions for practice or timing tests.Local onlyOpen toolBeat CounterEstimate BPM by tapping the pulse with clicks or the spacebar.Local onlyOpen toolDelay CalculatorConvert BPM to musical delay times and milliseconds to acoustic distance.Local onlyOpen toolPayload LabFormat, validate, and share JSON payloads without leaving the browser.Local onlyOpen toolType CheckerValidate in the browser whether a JSON payload is assignable to a root TypeScript type.Local onlyOpen toolJWT PlaygroundInspect JWT headers, payloads, and expiration locally without sending the token anywhere.Local onlyOpen toolDNS InspectorQuery live DNS records, including MX, TXT, NS, A, and AAAA, without leaving the workbench.Makes network callsOpen toolIPv4/Subnet CalculatorCalculate network, broadcast, mask, wildcard and usable hosts from CIDR.Local onlyOpen toolWHOIS / RDAPQuery public domain registration data with RDAP, the modern WHOIS replacement.Makes network callsOpen toolCertificate ExpiryInspect live TLS certificates, issuer details, and remaining validity before they become an outage.Makes network callsOpen toolHash & DigestGenerate SHA-1/256/384/512 digests (hex and base64) entirely in your browser.Local onlyOpen toolObject to TypesGenerate TypeScript interfaces and aliases directly from a real JSON object.Local onlyOpen toolRandom String GeneratorGenerate quick strings for secrets, IDs, demos, or fixtures in one place.Local onlyOpen toolEncoder / DecoderBase64, base64url, hex and URL encode/decode (UTF-8) in your browser.Local onlyOpen toolUUID / ULIDGenerate UUID v4 and ULID identifiers in batches, in your browser.Local onlyOpen toolObject ComparatorCompare two JSON objects and surface structural differences in seconds.Local onlyOpen toolRegex TesterTest regex patterns against multiline input with live highlight and group capture.Local onlyOpen toolText DiffCompare two texts line by line (LCS) entirely in your browser.Local onlyOpen toolMermaid DiagramsEdit and render Mermaid diagrams (flowchart, sequence, UML…) in your browser.Local onlyOpen toolSite CheckerMonitor URLs from the browser only, with local checks and desktop notifications.Makes network callsOpen toolSnippets ShelfStore quick notes, recipes, and frequent fragments locally.Local onlyOpen toolMarkdown NotesLocal-first markdown notes with a live preview, in your browser.Local onlyOpen toolPattern LessonsInteractive modern-pattern lessons with editable code and a sandboxed runner.Local onlyOpen toolCron ExpressionParse cron expressions and preview next run times with a field breakdown — no server needed.Local onlyOpen toolColor ToolsConvert HEX, RGB, HSL; pick colors and inspect WCAG contrast ratios — all in your browser.Local onlyOpen toolTimestamp ConverterConvert Unix timestamps and date strings to ISO, UTC, relative and more formats.Local onlyOpen toolNumber Base ConverterConvert between decimal, hexadecimal, binary and octal with a bit-field visualizer.Local onlyOpen toolJSON Schema GeneratorInfer a JSON Schema from any JSON sample with format detection and required-field analysis.Local onlyOpen toolURL Parser & BuilderParse URLs, inspect query params and build modified URLs — all in your browser.Local onlyOpen toolImage to Base64Convert images to data URIs, base64, CSS snippets or HTML img tags.Local onlyOpen tool
