Developer Studio · 46 tools
Developer Tools
55 free developer tools: regex tester, JWT debugger, cron parser, diff checker, timestamps, cURL converter and network calculators.
Part of Developer Studio.
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Regex Tester Advanced
Flags, groups, replace, cheat sheet.
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Diff Checker
Line-by-line visual differences.
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JWT Debugger
Decode JWT segments and verify.
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Unix Timestamp
Unix — human date + live now.
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Cron Parser
Explain cron and next 10 run times.
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cURL Builder
Build cURL command from form.
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HMAC Generator
Compute HMAC message authentication codes with SHA-1, SHA-256, SHA-384 or SHA-512 and a secret key, in hex or base64.
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JSON to Query String
Convert a JSON object into a URL query string with bracket notation for nested objects and arrays, fully percent-encoded.
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Date Format Calc
20+ date format conversions.
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Number Formatter
Format numbers with locale-aware thousands separators and fixed decimals using the Intl API — US, EU, Indian and more.
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cURL Builder
Build cURL command from form.
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Case Converter (Dev)
Convert identifiers between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, Title and Sentence case.
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cURL to Code
Convert cURL to JS/Python/PHP/Go.
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HTML Entities Ref
Search HTML entities quickly.
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String Escaper
Escape/unescape for JSON, JS, HTML, SQL, Regex and Shell.
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URL Encoder / Decoder
Percent-encode or decode text for URLs using encodeURIComponent or encodeURI, in both full-string and component modes.
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URL Parser
Parse full URL structure.
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HMAC Generator
Compute HMAC message authentication codes with SHA-1, SHA-256, SHA-384 or SHA-512 and a secret key, in hex or base64.
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Basic Auth Generator
Build an HTTP Basic Authorization header from user/pass.
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Cron Generator
Build cron from schedule dropdowns.
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CSS Clamp Generator
Generate a fluid CSS clamp() for responsive typography or spacing that scales linearly between two viewport widths.
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Hash Generator Advanced
MD5/SHA1/SHA256/SHA512 side-by-side.
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JWT Generator (HS256)
Sign a JSON Web Token with HMAC-SHA256 from your header, payload and secret — output verifiable against jwt.io.
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Query String Builder
Build and encode query strings.
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UUID v5 Generator
Generate deterministic RFC 4122 v5 UUIDs by SHA-1 hashing a name within a namespace (DNS, URL, OID, X.500 or custom).
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Cron Parser
Explain cron and next 10 run times.
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Diff Checker
Line-by-line visual differences.
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JWT Debugger
Decode JWT segments and verify.
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Regex Tester Advanced
Flags, groups, replace, cheat sheet.
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UUID Inspector
Detect UUID version, variant and embedded timestamp.
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Crontab Guru
Visual cron builder + readable output.
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Regex Cheatsheet
Regex patterns with live test.
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Timestamp Diff
Compute the difference between two dates or Unix timestamps in days, hours, minutes, seconds and a humanized string.
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User-Agent Parser
Extract browser/OS/device/engine.
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ASCII Table
0-127 searchable ASCII reference.
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Color Names Ref
CSS named colors palette.
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CSS Units Ref
All CSS units with preview.
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Git Cheatsheet
Interactive Git command guide.
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HTTP Headers Ref
Common request/response headers.
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HTTP Status Codes
Searchable HTTP code reference.
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Linux Commands Ref
Search Linux commands + examples.
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MIME Types
Extension — MIME lookup.
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IP Info
IPv4/IPv6 class/type/binary info.
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Unix Timestamp
Unix — human date + live now.
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Bytes Humanizer
Turn raw byte counts into human-readable sizes in KiB/MiB (binary) or KB/MB (decimal), and parse sizes back to bytes.
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Chmod Calculator
Symbolic — octal permission grid.
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CIDR Calculator
Network range, netmask, hosts.
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Duration Humanizer
Convert milliseconds or seconds into a readable duration like 1d 2h 3m 4s, and break it down across every time unit.
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Lorem Ipsum Advanced
Words/sentences/paragraphs generator.
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Meta Tags Advanced
SEO + OG + Twitter meta generator.
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Semver Tools
Validate, compare and range-check semantic versions.
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Slugify
Convert any text into a clean URL slug — strips accents, lowercases and joins words with a custom separator.
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Timezone Dev
Major timezone clock table.
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About Developer Tools
This category has 55 utilities that developers reach for during a normal working day. The Regex Tester highlights matches and groups and previews replacements, the JWT Debugger decodes token headers and claims and can verify a signature, and the Cron Parser explains a schedule in words and lists the next run times. The Diff Checker compares two texts line by line, and the Unix Timestamp converter turns epoch seconds into readable dates.
Network helpers include a CIDR calculator, a user-agent parser and an IP analyser that classifies addresses without any lookup request. You will also find a cURL-to-code converter for JavaScript, Python, PHP and Go, chmod and semver calculators, and quick references for HTTP status codes, MIME types and Git commands. Everything runs locally in the page, which matters when the text you paste includes tokens, internal hostnames or customer data.
Frequently asked questions
Can the JWT debugger verify signatures?
Which regex flavour does the tester use?
Does the IP tool show my location?
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