devtools.supstudio.in
Small tools. Clear answers. No account.
A multi-tool bench for schedules, tokens, JSON, encodings, and time. Everything you type stays in the browser unless you opt into the optional AI describe step.
Tools
Cron Expression Builder
Build, explain, and preview cron schedules. Next runs across timezones plus copy-paste snippets for GitHub Actions, Kubernetes, AWS, and more.
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JWT Decoder
Decode header and payload, verify HS256/RS256/ES256 in the browser, inspect exp/nbf/iat, and read every claim. Tokens never leave this tab.
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Regex Tester
JavaScript regex tester with live highlights, groups, a token explainer, replace, and optional English → pattern.
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Timestamp Converter
Unix seconds, milliseconds, ISO 8601, and RFC 2822. Live clock, IANA zones, batch convert, Y2038.
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JSON Formatter
Beautify, minify, validate, repair JS-ish JSON, tree viewer, table, JSONPath, CSV/YAML. Payload stays in this tab.
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Base64 Encoder
UTF-8 Base64 and base64url. Hex dump, file to data URI. The encoding under JWT and HTTP Basic.
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UUID Generator
UUID v4, time-ordered v7, name-based v5, nil, and a validator. Web Crypto — not Math.random.
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Popular cron schedules
- Cron for every minute* * * * *
- Cron for every 5 minutes*/5 * * * *
- Cron for every 10 minutes*/10 * * * *
- Cron for every 15 minutes*/15 * * * *
- Cron for every 30 minutes*/30 * * * *
- Cron for every hour0 * * * *
- Cron for every day at midnight0 0 * * *
- Cron for every day at 9am0 9 * * *
- Cron for every weekday at 9am0 9 * * 1-5
- Cron for every Monday at 9am0 9 * * 1
- Cron for every Sunday at midnight0 0 * * 0
- Cron for the first of the month at midnight0 0 1 * *
Cron by platform
Timezones: UTC · New York · Los Angeles · Chicago · London · Paris · Berlin · India (Kolkata) · Tokyo · Singapore · Dubai · Sydney