Developer Utilities

Everyday utilities for developers.

149 tools

.editorconfig Generator Generate a .editorconfig from a few options.
.gitignore Generator Build a .gitignore for any combination of languages and stacks.
.nvmrc Helper Pick a Node.js version and generate a .nvmrc.
AI Commit Message Generator Turn a git diff or change summary into a Conventional Commit message.
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ANSI Escape Reference Searchable cheatsheet of ANSI / CSI terminal codes.
Antenna Length Calculator Quarter-wave, half-wave and full-wave antenna lengths for a target frequency.
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Apache Virtual Host Builder Generate an Apache <VirtualHost> block from a small form.
Arduino / RPi / ESP32 Pinout Reference Pin function reference for common Arduino, Raspberry Pi GPIO and ESP32 boards.
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ASCII Banner Text Render text as a multi-line ASCII art banner.
AWG Voltage Drop & Ampacity (DC) Voltage drop and ampacity table for DC circuits (12V, 24V, 48V) over a wire run.
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AWS ARN Parser Split an AWS ARN into partition, service, region, account and resource.
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Azure Blob Storage Explorer Browse and modify Azure Blob Storage — list containers and blobs, upload, download, rename, move and delete.
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Base64 Encoder / Decoder Encode text to Base64 or decode Base64 back to plain text.
Bash <-> PowerShell Translator Translate Bash one-liners to PowerShell and vice versa using a rules table.
Bash Cheat Sheet Searchable reference for everyday Bash commands.
Basic Auth Header Builder Build an HTTP Basic Authorization header and curl snippet from credentials.
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Capacitor Code Reader Decode 3-digit ceramic / film capacitor codes (e.g. 104 = 0.1 μF).
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Chat Transcript Formatter Turn an OpenAI/Anthropic messages array into a readable markdown transcript.
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Chmod Calculator Toggle Linux file permission bits and read both numeric and symbolic chmod.
Cisco Type 7 Password Decoder Reversible decode (and encode) of Cisco IOS Type 7 obfuscated passwords.
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Code Explainer (AI) Paste code and get a clear, step-by-step walkthrough of what it does.
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Color Code Converter Convert HEX ↔ RGB ↔ HSL ↔ HSV in one step.
Connection String Parser & Builder Parse a database connection string, mask the password, and convert between ADO.NET and URL DSN forms.
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Context Window Budget Planner Add up prompt components against a model's context window and see what's left.
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Conventional Commit Builder Compose a properly formatted Conventional Commits message.
Cron Expression Parser Parse a cron expression and translate it to plain English.
Cron from English (AI) Describe a schedule in plain English and get the matching cron expression.
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Cron Next-N Runs Compute the next N UTC firings of a cron expression from a start date.
Cron → Quartz / EventBridge Convert Unix cron to Quartz or AWS EventBridge expression form.
CSS Selector Tester Run a simple CSS selector against pasted HTML.
CSS Specificity Calculator Calculate selector specificity as ID, class and element weights.
CSS Variables → SCSS Rewrite CSS custom properties and var() calls as SCSS $variables.
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CSS → Tailwind Suggestions Suggest Tailwind utility classes for a block of CSS.
dBm ↔ Watts / dB Ratios Convert between dBm, watts and dB ratios for RF power calculations.
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Docker Run to Compose Converter Convert a docker run command into a Docker Compose service.
Dockerfile Linter Check Dockerfiles for common security and portability issues.
Dockerfile Linter Pro Lint Dockerfiles for security, cache and bloat issues with rule ids and line numbers.
Dotenv → Kubernetes Secret / ConfigMap Turn .env lines into a Kubernetes Secret (base64) or ConfigMap manifest.
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Env File Doctor Lint .env files for duplicates, malformed lines, inline comments and likely secret leaks.
ENV File Parser / Validator Validate .env syntax and inspect key/value pairs.
envsubst Renderer Substitute ${VAR} placeholders against a JSON or .env environment.
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Error Message Explainer (AI) Paste a stack trace or error and get a plain-language explanation plus a fix.
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Fluid Type Scale (CSS clamp) Builder Build a full responsive type scale of CSS clamp() font sizes that fluidly interpolate between two viewport widths (Utopia method).
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Font Pairing Suggester Suggest heading and body Google Font pairings with rationale, @import lines and ready-to-use font-family CSS stacks.
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Gettext .po Parser Parse a gettext .po file and list its entries.
git log Command Builder Assemble a git log command from form inputs.
Glob Pattern Tester Test a glob pattern (** ? *) against a path list, and show its regex.
GraphQL Query Formatter Pretty-print a GraphQL query or mutation and list its declared variables.
GraphQL Schema Formatter Format and validate GraphQL schema definitions.
HAR Waterfall Render a HAR file as a waterfall with status filters and per-entry headers.
HCL / Terraform Formatter Re-indent HCL/Terraform with two-space blocks and spaced assignments (terraform fmt style).
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HOTP Generator Generate counter-based one-time passwords using RFC 4226 HOTP.
HTML / CSS / JS Minifier Minify HTML, CSS or JavaScript safely.
HTML Accessibility Linter Heuristically scan HTML for common accessibility problems and report errors and warnings.
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HTML Encoder / Decoder Escape or unescape HTML entities like &, <, >.
htpasswd Entry Generator Generate APR1-MD5 or SHA-1 entries for .htpasswd files.
HTTP Header Reference Searchable reference for common HTTP request and response headers.
HTTP Status Codes Searchable reference of all standard HTTP status codes.
HTTP/2 Header Compression Explainer Explain how HPACK compresses repeated HTTP/2 headers.
ICU MessageFormat Tester Render an ICU MessageFormat template with plural/select arms.
Indent / Whitespace Detector Detect whether a file uses tabs, 2-space or 4-space indentation.
IP CIDR Notation Builder Suggest CIDR notation for IP ranges.
I²C Device Address Reference Common 7-bit I²C addresses for popular sensors and breakouts.
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jq-lite Playground Evaluate a jq-style path filter against pasted JSON.
JSON Schema Bulk Sampler Generate N sample records matching a JSON Schema, with seed control and optional field variation.
JSON Schema Diff Diff two JSON schemas: added, removed and changed field types.
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JSON Schema Sample Generator Generate an example document from a JSON Schema.
JSON Sort Keys Recursively sort object keys in a JSON document alphabetically.
JSON to Dart Class Generate Dart classes from a JSON sample.
JSON to PHP Class Generate PHP classes from a JSON sample.
JSON to Pydantic Model Generate Pydantic BaseModel classes from a JSON sample.
JSON to Rust Struct Generate Rust serde-derive structs from a JSON sample.
JWK to PEM Convert an RSA or EC JSON Web Key (public or private) into a PEM-encoded key.
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JWT Crafter Sign and verify JWTs with HS256/384/512 or RS256/384/512 keys.
JWT Decoder Decode a JWT to inspect its header, payload and signature.
Kubernetes Label Selector Tester Match a set of labels against a Kubernetes label selector expression.
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Kubernetes YAML Linter Fast best-practice checks for a Kubernetes manifest.
LaTeX → Unicode Math Convert LaTeX math commands like \alpha, \int to Unicode symbols.
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LED Series Resistor Calculator Compute the dropping resistor for an LED at a given supply voltage and current.
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License Compatibility Checker Check whether two software licenses can be combined.
License Generator Generate a LICENSE file for MIT, Apache, GPL, BSD, ISC or Unlicense.
Lines of Code Counter cloc-style code, comment and blank line breakdown for pasted text.
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Liquid Template Tester Render a small Liquid template against JSON data.
LLM API Cost Estimator Estimate per-call and at-scale LLM API cost from token counts and prices.
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LLM Token Counter (estimate) Estimate the token count of a prompt for GPT/Claude-style BPE tokenisers.
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logfmt Parser Parse Heroku-style key=value log lines into a table.
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Makefile Parser Extract targets, variables and includes from a Makefile.
Markdown Frontmatter Extractor Split a Markdown document into YAML/TOML frontmatter and body.
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Markdown Linter Spot trailing whitespace, long lines and bad heading order in Markdown.
Markdown TOC Generator Build a table of contents from Markdown headings.
Mermaid Template Gallery Copy-ready Mermaid diagram templates for GitHub, GitLab and Notion.
MIME Type Lookup Look up the MIME type for a file extension (and vice versa).
Modular Type Scale Generator Generate a modular typographic scale with px/rem sizes, CSS custom properties and a Tailwind fontSize config.
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Multipart Form-Data Builder Build a raw multipart/form-data request body and header from key: value fields.
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Mustache / Handlebars Tester Render a Mustache template against JSON data.
Naming Helper (AI) Describe a variable, function or class and get clear name suggestions across casings.
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nginx Config Builder Generate a reverse-proxy or static-site nginx server block.
Ohm's Law / Power Triangle Fill any two of V, I, R, P; computes the others using Ohm's Law and P = VI.
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Op-Amp Gain Calculator Closed-loop gain for inverting / non-inverting / difference amplifier topologies.
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OpenAPI / Swagger Viewer List the endpoints in an OpenAPI (Swagger) JSON document.
OpenAPI Snippet Exporter Export cURL, HTTPie, Postman v2.1 and JS fetch snippets from an OpenAPI spec.
OpenSSL Command Builder Find the right OpenSSL command for keys, CSRs, certs, PKCS#12 and encryption.
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package.json Generator Generate a clean package.json from a small form.
PCB Trace Width (IPC-2221) Compute external/internal PCB trace width for a given current and temperature rise.
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PEM to JWK Convert an RSA or EC key in PEM form into a JSON Web Key (public or private).
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POSIX / PCRE Regex Translator Translate regex between POSIX character classes and PCRE shorthand.
Postman Collection Viewer List every request in a Postman v2.x collection export.
PowerShell Cheat Sheet Searchable reference for everyday PowerShell cmdlets.
Pre-commit Hook Generator Build a .pre-commit-config.yaml from common hooks.
prefers-reduced-motion & color-scheme Helper Generate CSS and JS scaffolding for prefers-reduced-motion and prefers-color-scheme plus a manual test checklist.
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Protobuf ↔ JSON Converter Decode a hex/base64 protobuf message against a .proto schema, or preview the wire bytes for a JSON payload.
Python dict → JSON Convert a Python dict/list literal (True/False/None, single quotes) into JSON.
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Query String ↔ JSON Convert a URL query string to a JSON object and back.
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RC Time Constant Calculator Compute an RC circuit's time constant, cutoff frequency and charge curve.
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README Generator Scaffold a project README from a small form.
Redis Explorer Connect to a Redis server and browse keys — scan by pattern, view values by type, set, delete and run raw commands.
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Regex Cheat Sheet Quick reference for regular expression syntax across flavours.
Regex from English (AI) Describe a pattern in plain English and get a tested regular expression with examples.
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Regex Tester Pro Test .NET regex with capture groups, named groups, replacements, presets and a built-in cheat sheet.
REPL Prompt Stripper Strip $, >>> and other REPL prompts from a pasted code block.
Resistor Color Band ↔ Value Decode 3/4/5-band resistor color codes to resistance and tolerance.
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S3 Explorer Browse and modify S3 buckets — upload, download, presign, copy, rename and delete objects.
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Semantic Release Preview Given a current version and conventional-commit list, suggest the next version.
Semantic Version Comparator Compare semantic version numbers and see which is newer.
Series / Parallel Resistor Calculator Combine resistors in series or parallel and see both totals.
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Snowflake ID Decoder Decode the timestamp and worker fields from a Twitter/Discord snowflake ID.
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Sourcemap Lookup Resolve a generated line:column to original source via a v3 source map.
Spacing Token Scale Generator Generate spacing design tokens (linear or modular) as CSS custom properties, a Tailwind spacing object and an SCSS map.
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SQL Dialect Translator Translate SQL between PostgreSQL, MySQL, SQL Server and SQLite dialects.
SQL EXPLAIN Visualizer Render a Postgres / MySQL / SQL Server query plan as a collapsible tree with cost highlights.
SQL from a Question (AI) Turn a plain-English question plus your schema into a ready-to-run SQL query.
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SQL IN-Clause Builder Turn a list of values into one or more SQL 'column IN (...)' clauses with smart quoting and chunking.
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SVG Minifier Minify SVG markup by removing extra whitespace.
SVG → JSX Convert SVG attributes to JSX (className, camelCase props) for React.
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Syslog RFC 5424 Parser Decode a Syslog RFC 5424 message: priority, facility, severity, structured data.
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System Prompt Linter Flag vague phrasing, conflicting goals and missing examples in an LLM system prompt.
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systemd Unit File Generator Build a systemd .service unit from a form.
Tab / Focus Order Visualizer Compute and list the keyboard Tab order of focusable elements in an HTML snippet.
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Tailwind Class Sorter Reorder Tailwind utility classes into a consistent, readable order.
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Tailwind Config Validator Check a tailwind.config.js for common mistakes.
TCP / UDP Port Reference Look up well-known TCP and UDP port assignments.
TypeScript <-> C# DTO Converter Convert a TypeScript interface or C# class/record to the other language.
Unicode Escape / Unescape Convert non-ASCII characters to \uXXXX escapes and back again.
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Unified Diff Parser Parse and visualise unified diff or git diff output.
Unix Timestamp Converter Convert between Unix timestamps and human dates.
URL Encoder / Decoder Percent-encode URLs or decode them back to readable form.
UUID Generator Generate v4 / v7 UUIDs (GUIDs) with one click.
Voltage Divider Calculator Output voltage for a two-resistor divider; also suggests R-pair for a target Vout.
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XPath Tester Evaluate an XPath expression against pasted XML.