Developer tools directory
General-purpose utilities for developers that do not fit a narrower category.
184 tools in this category, all running in your browser.
Tools in Developer
Percentage Calculator
/tools/percentage-calculator/Calculate a percentage of a number, what percent one number is of another, or percent change.
Unit Converter
/tools/unit-converter/Convert a value between length, mass, temperature, data-size, and time units.
Timestamp Converter
/tools/timestamp-converter/Convert between Unix timestamps in seconds or milliseconds and ISO-8601 instants.
JSON Formatter
/tools/json-formatter/Format and validate JSON while preserving large integers.
JSON Validator
/tools/json-validator/Check whether a document is valid JSON and report the first syntax error with its position.
UUID Generator
/tools/uuid-generator/Generate RFC 9562 version 4 (random) or version 7 (time-ordered) UUIDs.
Base64 Encoder / Decoder
/tools/base64-encoder/Encode UTF-8 text to Base64 or decode Base64 back to UTF-8 text.
URL Encoder / Decoder
/tools/url-encoder/Percent-encode or decode URL text, for whole URLs or single components.
Cron Expression Generator
/tools/cron-expression-generator/Validate a five-field cron expression, describe it, and list its next run times.
Text Counter
/tools/text-counter/Count characters, words, lines, sentences, and paragraphs, and estimate reading time.
Regex Tester
/tools/regex-tester/Test a regular expression against a subject and inspect matches and capture groups.
Diff Checker
/tools/diff-checker/Compare two texts line by line in your browser, with side-by-side or unified views and no upload.
JSON Compare
/tools/json-compare/Compare two JSON documents semantically in your browser: key-order and whitespace-insensitive, type-aware, with exact number literals and RFC 6901 paths.
Case Converter
/tools/case-converter/Convert text between lower, upper, title, camel, snake, kebab and constant case.
JSON Minifier
/tools/json-minifier/Remove all insignificant whitespace from JSON while preserving every value.
JSON Beautifier
/tools/json-beautifier/Pretty-print JSON with 2-space, 4-space or tab indentation.
JSON CSV Converter
/tools/json-csv-converter/Convert JSON to CSV and CSV back to JSON in the browser.
JSON XML Converter
/tools/json-xml-converter/Convert JSON to XML and XML back to JSON in the browser.
JSON YAML Converter
/tools/json-yaml-converter/Convert JSON to YAML and YAML back to JSON in the browser.
JSONPath Query
/tools/jsonpath/Query JSON with JSONPath and see every match with its JSON Pointer path.
JSON Pointer
/tools/json-pointer-resolver/Resolve an RFC 6901 JSON Pointer against a JSON document.
JSON Schema Validator
/tools/json-schema-validator/Validate JSON against a JSON Schema subset and list every violation.
JSON Sort Keys
/tools/json-sort-keys/Sort every object key recursively for stable, deterministic JSON.
Base64URL Encoder / Decoder
/tools/base64url-encoder/Encode UTF-8 text to URL-safe Base64 or decode a Base64URL value back to text.
Base32 Encoder / Decoder
/tools/base32-encoder/Encode UTF-8 text to RFC 4648 Base32 or decode a Base32 value back to text.
Base58 Encoder / Decoder
/tools/base58-encoder/Encode UTF-8 text to Base58 (Bitcoin alphabet) or decode a Base58 value back to text.
Base62 Encoder / Decoder
/tools/base62-encoder/Encode UTF-8 text to Base62 or decode a Base62 value back to text.
ASCII85 Encoder / Decoder
/tools/ascii85-encoder/Encode UTF-8 text to Adobe ASCII85 or decode an ASCII85 value back to text.
ASCII / Unicode Code Converter
/tools/ascii-encoder/Convert text to space-separated Unicode code points and back.
Hex Encoder / Decoder
/tools/hex-encoder/Encode UTF-8 text to hexadecimal byte pairs or decode hex back to text.
Binary Encoder / Decoder
/tools/binary-encoder/Encode UTF-8 text to space-separated 8-bit binary groups or decode binary back to text.
Octal Encoder / Decoder
/tools/octal-encoder/Encode UTF-8 text to space-separated octal byte groups or decode octal back to text.
Number Base Converter
/tools/number-base-converter/Convert an integer between any two bases from 2 to 36 with arbitrary-precision arithmetic.
Slug Generator
/tools/slug-generator/Convert text to a URL-safe slug with a chosen separator.
Line Counter
/tools/line-counter/Count lines, blank lines, words and characters in text.
Whitespace Cleaner
/tools/whitespace-cleaner/Trim, collapse and remove whitespace from text.
Duplicate Line Remover
/tools/duplicate-line-remover/Remove duplicate lines while keeping the first or last occurrence.
Text Sorter
/tools/text-sorter/Sort lines alphabetically or numerically in either direction.
Text Deduplicator
/tools/text-deduplicator/Remove duplicate lines, words or comma-separated items.
Regex Generator
/tools/regex-generator/Build a safe regular expression from curated patterns.
HTML Formatter
/tools/html-formatter/Indent and format HTML markup with consistent line breaks.
CSS Formatter
/tools/css-formatter/Indent and format CSS rules, selectors and declarations.
JavaScript Formatter
/tools/js-formatter/Indent and format JavaScript while preserving line-break semantics.
XML Formatter
/tools/xml-formatter/Indent and format well-formed XML documents.
YAML Formatter
/tools/yaml-formatter/Normalise YAML indentation and trailing whitespace.
SQL Formatter
/tools/sql-formatter/Lay out SQL clauses on their own lines with optional keyword upper-casing.
Markdown Formatter
/tools/markdown-formatter/Normalise Markdown headings, lists, blank lines and fences.
HTML Minifier
/tools/html-minifier/Remove HTML comments and redundant whitespace safely.
CSS Minifier
/tools/css-minifier/Remove CSS comments, redundant whitespace and empty rules.
JavaScript Minifier
/tools/js-minifier/Remove JavaScript comments and redundant whitespace while preserving ASI semantics.
Timezone Converter
/tools/timezone-converter/Convert an instant between IANA timezones with offset, DST and day-shift.
World Clock
/tools/world-clock/Show the current time in any set of IANA timezones.
ISO 8601 Parser
/tools/iso-8601-parser/Parse ISO 8601 dates, times, durations and intervals into their parts.
Relative Time
/tools/relative-time/Describe the distance between two instants in words and parts.
URL Parser
/tools/url-parser/Parse an absolute URL into scheme, host, port, path, query parameters and fragment, with optional percent-decoding.
URL Builder
/tools/url-builder/Compose a URL from scheme, host, port, path, query parameters and fragment with correct percent-encoding.
Hash Generator
/tools/hash-generator/Compute SHA-1, SHA-256, SHA-384, SHA-512 and MD5 message digests in your browser.
HMAC Generator
/tools/hmac-generator/Compute a keyed HMAC-SHA-1/256/384/512 message authentication code without your key leaving the browser.
Checksum Generator
/tools/checksum-generator/Compute CRC-32, Adler-32 and FNV-1a checksums in hexadecimal and decimal.
HTTP Header Parser
/tools/http-header-parser/Parse a raw HTTP header block into named fields, values, duplicate groups and malformed-line warnings.
User-Agent Parser
/tools/user-agent-parser/Classify a User-Agent string into browser, engine, operating system, device class and bot flag.
Basic Auth Generator
/tools/basic-auth-generator/Build an RFC 7617 Basic Authorization header value from a username and password without the credential leaving the browser.
HTTP Status Lookup
/tools/http-status-lookup/Look up RFC 9110 HTTP status codes by number or phrase with class, description and reference.
cURL Generator
/tools/curl-generator/Compose a copy-pasteable, shell-escaped curl command from a method, URL, headers and body.
HTTP Request Builder
/tools/http-request-builder/Compose a well-formed HTTP/1.1 request message from a method, target, headers and body without sending it.
CORS Helper
/tools/cors-helper/Reference the CORS request and response headers and build guidance response headers for an origin, method and credentials mode.
OpenAPI Viewer
/tools/openapi-viewer/Parse an OpenAPI 3.x or Swagger 2.0 document in JSON or YAML and render its structure in the browser.
OpenAPI Converter
/tools/openapi-converter/Convert OpenAPI JSON to YAML and back, or generate a minimal OpenAPI 3.1 skeleton, in the browser.
Password Generator
/tools/password-generator/Generate cryptographically secure random passwords with a chosen length and character classes.
API Key Generator
/tools/api-key-generator/Generate prefixed, high-entropy API keys with your browser's cryptographic random source.
Random Token Generator
/tools/random-token-generator/Generate cryptographically secure random tokens in hex, base64url, base32 and base58 encodings.
Password Hash Tool
/tools/password-hash-tool/Derive and verify PBKDF2 password hashes in your browser, and inspect bcrypt and Argon2 hash formats with their limits stated.
JWT Encoder & Verifier
/tools/jwt-tool/Encode and verify HMAC-signed JWTs (HS256, HS384, HS512) in your browser and check their time claims.
PEM & Certificate Helper
/tools/pem-certificate-helper/Inspect PEM blocks, convert PEM to and from base64 DER, and compute certificate fingerprints locally.
OpenSSL Command Generator
/tools/openssl-command-generator/Build copy-pasteable OpenSSL commands for keys, certificates and encryption without running them.
AES Encryption Tool
/tools/encryption-tool/Encrypt and decrypt text with AES-256-GCM in your browser, with the key derived locally from a passphrase.
Entropy Calculator
/tools/entropy-calculator/Measure the Shannon entropy and brute-force search space of a password or token in your browser.
Gitignore Generator
/tools/gitignore-generator/Generate a .gitignore from selected ecosystems in your browser.
Gitattributes Generator
/tools/gitattributes-generator/Generate a .gitattributes with line-ending, binary and diff rules.
Git Command Lookup
/tools/git-command-lookup/Look up real Git commands by task with syntax and examples.
Dockerfile Generator
/tools/dockerfile-generator/Generate a multi-stage Dockerfile for your stack.
Docker Compose Generator
/tools/docker-compose-generator/Generate a docker-compose.yml with app, database and cache services.
GitHub Actions Generator
/tools/github-actions-generator/Generate a GitHub Actions workflow with triggers, setup and steps.
GitLab CI Generator
/tools/gitlab-ci-generator/Generate a .gitlab-ci.yml with stages and jobs.
Jenkinsfile Generator
/tools/jenkinsfile-generator/Generate a declarative Jenkinsfile pipeline.
Kubernetes YAML Generator
/tools/kubernetes-yaml-generator/Generate a Kubernetes Deployment and Service manifest in your browser.
Terraform Config Generator
/tools/terraform-config-generator/Generate Terraform provider, resource, variable and output blocks in your browser.
Helm Values Helper
/tools/helm-values-helper/Generate a Helm Chart.yaml and values.yaml scaffold in your browser.
Nginx Config Generator
/tools/nginx-config-generator/Generate an nginx server block with TLS and a proxy pass in your browser.
Apache VirtualHost Generator
/tools/apache-vhost-generator/Generate an Apache VirtualHost with a proxy pass and HTTPS redirect in your browser.
OpenTelemetry Config Generator
/tools/opentelemetry-config-generator/Generate an OpenTelemetry Collector configuration in your browser.
AWS Cron Validator
/tools/aws-cron-validator/Validate and explain an AWS EventBridge six-field cron expression in your browser.
Env File Generator
/tools/env-file-generator/Generate a placeholder-only .env, shell, Compose or Kubernetes environment file in your browser.
Config Converter
/tools/config-converter/Convert between flat .env, properties, INI and JSON config formats in your browser.
DNS Lookup
/tools/dns-lookup/Look up A, AAAA, CNAME, MX, TXT and NS records for a hostname.
DNS Record Parser
/tools/dns-record-parser/Parse pasted DNS zone or dig output into structured records.
DNS Propagation Checker
/tools/dns-propagation-checker/Compare a DNS record across resolvers and check propagation.
WHOIS Lookup
/tools/whois-lookup/Look up domain registration and WHOIS data.
ASN Lookup
/tools/asn-lookup/Look up the autonomous system for an IP address or ASN.
SERP Preview
/tools/serp-preview/Preview a Google desktop and mobile search result for a page.
Title & Meta Checker
/tools/title-meta-checker/Audit a page title and meta description for length and quality.
robots.txt Generator
/tools/robots-txt-generator/Generate a robots.txt from user-agent rules and sitemaps.
Sitemap Validator
/tools/sitemap-validator/Validate an XML sitemap against the sitemaps.org protocol.
Sitemap Generator
/tools/sitemap-generator/Generate a valid XML sitemap from a list of URLs.
Canonical Checker
/tools/canonical-checker/Check a canonical URL for common duplicate-content risks.
Open Graph Generator
/tools/open-graph-generator/Generate Open Graph meta tags for a page.
Twitter/X Card Generator
/tools/twitter-card-generator/Generate Twitter/X card meta tags for a page.
Structured Data Generator
/tools/structured-data-generator/Generate valid JSON-LD structured data for a page.
JSON-LD Helper
/tools/json-ld-helper/Format, validate and inspect JSON-LD structured data.
UTM Campaign URL Builder
/tools/utm-builder/Build a UTM-tagged campaign URL with validated parameters.
ads.txt Generator
/tools/ads-txt-generator/Generate an IAB ads.txt seller line with validation.
Favicon Generator
/tools/favicon-generator/Generate a browser-ready SVG favicon and link tags.
App Icon Generator
/tools/app-icon-generator/Generate a web app manifest and maskable icon set.
Social Preview
/tools/social-preview/Preview how a link renders across social platforms.
Image Converter
/tools/image-converter/Convert an image between PNG, JPEG, WebP and AVIF locally in your browser.
Image Resizer
/tools/image-resizer/Resize an image to exact dimensions or a percentage, optionally locking the aspect ratio.
Image Compressor
/tools/image-compressor/Re-encode an image at a chosen quality to reduce its byte size, and compare before and after.
Image Metadata Viewer
/tools/image-metadata/Read PNG, JPEG, WebP and GIF metadata — dimensions, EXIF, IPTC, XMP and PNG chunks — locally.
SVG Viewer
/tools/svg-viewer/Preview an SVG safely and inspect its structure — viewBox, dimensions, shapes and colours.
SVG Optimizer
/tools/svg-optimizer/Safely shrink an SVG by removing comments, editor metadata and inter-tag whitespace.
SVG to PNG
/tools/svg-to-png/Rasterise an SVG to a PNG at a chosen scale, locally in your browser.
PDF Splitter
/tools/pdf-split/Split a PDF into every page, fixed-size parts or explicit page ranges, locally in your browser, and download each result.
PDF Merger
/tools/pdf-merge/Combine two or more PDFs into one document in a chosen order, locally in your browser, with a combined page count.
PDF Metadata Viewer
/tools/pdf-metadata/Read PDF metadata locally — version, page count and sizes, Info and XMP fields, and encryption/linearization flags — without editing or uploading the file.
PDF Page Extractor
/tools/pdf-page-extract/Extract selected pages from a PDF into a new document in the order you choose, locally in your browser.
PDF Page Rotator
/tools/pdf-page-rotate/Rotate selected PDF pages by 90, 180 or 270 degrees, leaving the other pages unchanged, locally in your browser.
PDF Page Remover
/tools/pdf-page-delete/Delete selected pages from a PDF and keep the rest in order, locally in your browser, refusing to produce an empty document.
CSV Viewer
/tools/csv-viewer/View CSV, TSV or PSV data as a table — auto-detected delimiter, row and column counts and per-column types — entirely in your browser.
Delimited Converter
/tools/delimited-converter/Convert delimited data between CSV, TSV, PSV and custom delimiters with configurable quoting — locally in your browser.
CSV to SQL
/tools/csv-to-sql/Generate SQL CREATE TABLE and batched INSERT statements from CSV, TSV or PSV data for standard, PostgreSQL, MySQL or SQLite — locally in your browser.
CSV to Markdown
/tools/csv-to-markdown/Convert CSV, TSV or PSV data into a GitHub-flavoured Markdown table or an HTML table, locally in your browser.
CSV Column Stats
/tools/csv-column-stats/Profile every column of CSV, TSV or PSV data — counts, uniqueness, inferred type and numeric min/max/mean — locally in your browser.
CSV Transpose
/tools/csv-transpose/Transpose CSV, TSV or PSV data — swap rows and columns — while preserving every cell, locally in your browser.
CSV Merge
/tools/csv-merge/Merge several CSV, TSV or PSV inputs into one table by header union or by position, reporting added and missing columns — locally in your browser.
SQL Validator
/tools/sql-validator/Check a SQL statement for structural problems such as unbalanced parentheses, unterminated strings or comments, and an unrecognised leading command, for PostgreSQL, MySQL, SQLite or T-SQL, locally in your browser.
SQL Safety Checker
/tools/sql-safety-checker/Scan SQL for destructive statements such as DROP, TRUNCATE, DELETE or UPDATE without a WHERE clause, ALTER ... DROP and privilege changes, and see each one explained, without ever running it.
SQL Parameter Formatter
/tools/sql-parameter-formatter/Rewrite SQL placeholders between styles such as ? , $1, :name, @name, %s or {0}, numbering positional parameters in order and listing the bindings, locally in your browser.
SQL Minifier
/tools/sql-minifier/Minify SQL by stripping comments and collapsing insignificant whitespace while keeping every string literal and quoted identifier byte-for-byte, locally in your browser.
SQL Query Analyzer
/tools/sql-query-analyzer/Analyse SQL structure: each statement's type, the referenced tables, joins, whether it filters with WHERE and how many parameters it binds, locally in your browser.
SQL Statement Splitter
/tools/sql-statement-splitter/Split a SQL script into numbered statements on top-level semicolons, keeping strings, quoted identifiers and comments intact, locally in your browser.
Markdown Editor
/tools/markdown-editor/Write Markdown with a sanitized live HTML preview and local-only autosave; nothing is uploaded and no code runs.
HTML Editor
/tools/html-editor/Write HTML with a sanitized live preview and local-only autosave; scripts, event handlers and external resources are removed.
HTML/CSS Playground
/tools/html-css-playground/Compose HTML and CSS and see a sanitized preview; pasted JavaScript is shown for reference but never executed. Local-only autosave.
CSV Editor
/tools/csv-editor/Edit CSV, TSV or pipe-delimited text and see it parsed into a table with local-only autosave; reuses the shared browser CSV parser.
Token Counter
/tools/token-counter/Count characters, words, lines and UTF-8 bytes and estimate LLM tokens locally, with the method and its limits stated.
Prompt Formatter
/tools/prompt-formatter/Normalize a prompt — line endings, trailing spaces, blank-line runs, bullet markers and wrapping — deterministically in your browser.
System Prompt Builder
/tools/system-prompt-builder/Compose a structured system prompt from role, objective, capabilities, constraints, tone and output format — locally in your browser.
JSON Schema Prompt Helper
/tools/json-schema-prompt-helper/Turn a JSON Schema into a natural-language output instruction that names every field, locally in your browser.
Model Pricing Calculator
/tools/model-pricing-calculator/Estimate model cost from input/output token counts and a cited, timestamped price catalog, or your own prices, locally.
Prompt Diff
/tools/prompt-diff/Compare two prompt versions line by line and see added, removed and changed lines plus the token and character delta — locally.
Structured Output Helper
/tools/structured-output-helper/Build a strict structured-output contract from a sample JSON value, or repair fenced/trailing-comma JSON into valid JSON — locally.
LLM API Request Generator
/tools/llm-request-generator/Generate a provider request (endpoint, placeholder key, JSON body and code) with the full disclosure of provider, model, cost, transmission, retention and key handling. Nothing is sent.
AI Website Scanner
/tools/ai-website-scanner/Scan a public page for AI-readiness signals — crawl policy, metadata, structured data and readable content — through a stateless SSRF-safe fetch.
Robots AI Crawler Helper
/tools/robots-ai-crawler-helper/Build a robots.txt policy for named AI crawlers, or analyze an existing robots.txt to see which AI crawlers it allows or blocks.
AGENTS.md Generator
/tools/agents-md-generator/Compose an AGENTS.md file for coding agents from your own project facts — setup, stack, tests, style and boundaries — with nothing invented.
CLAUDE.md Generator
/tools/claude-md-generator/Compose a CLAUDE.md memory file from your own project facts — overview, commands, stack, standards and boundaries — with nothing invented.
.cursorrules Generator
/tools/cursorrules-generator/Compose a .cursorrules file from your own project rules — nothing is invented and blank input is refused.
MCP Config Generator
/tools/mcp-config-generator/Generate a Model Context Protocol client config block and server command snippet from your own values — the tool produces text only and starts no server.
Bash Formatter
/tools/bash-formatter/Indent and format Bash shell scripts with consistent layout.
Python Formatter
/tools/python-formatter/Normalise Python indentation to a consistent width without changing blocks.
TypeScript Formatter
/tools/typescript-formatter/Indent and format TypeScript and JavaScript with preserved line breaks.
XML Minifier
/tools/xml-minifier/Minify XML by removing comments and inter-element whitespace.
YAML Minifier
/tools/yaml-minifier/Minify YAML by removing comments and blank lines and compressing indentation.
Markdown Minifier
/tools/markdown-minifier/Minify Markdown by trimming whitespace and collapsing blank lines.
Volume Converter
/tools/volume-converter/Convert a volume between metric and US/imperial units with exact factors.
Speed Converter
/tools/speed-converter/Convert a speed between metric and imperial units with exact factors.
Energy Converter
/tools/energy-converter/Convert energy between joule, calorie, watt-hour, BTU and electronvolt units.
Bitwise Calculator
/tools/bitwise-calculator/Apply bitwise AND, OR, XOR, NOT, NAND and NOR and bit shifts to integers.
Number Formatter
/tools/number-formatter/Format a number with grouping, fixed or significant precision and scientific notation.
Random Number Generator
/tools/random-number-generator/Generate cryptographically secure random integers or decimals within a range.
List Randomizer
/tools/list-randomizer/Shuffle, sample or pick from a list with a reproducible seed option.
CSS Specificity Calculator
/tools/css-specificity-calculator/Compute the specificity of a CSS selector and compare two selectors.
Asset Reference Checker
/tools/asset-reference-checker/Find relative asset and link references in HTML and CSS and check them against a file list.
.env Validator
/tools/dotenv-validator/Parse and validate dotenv content: syntax, duplicate keys and empty values.
Conventional Commit Generator
/tools/conventional-commit-generator/Build a Conventional Commits message from a type, scope, description and body.
Git Conflict Analyzer
/tools/git-conflict-analyzer/List the conflicted blocks in a file with conflict markers and their ours/theirs sides.
CSV Profiler
/tools/csv-profiler/Profile a CSV: per-column type, null count, unique count and min/max or length range.
Reverse DNS Lookup
/tools/reverse-dns-lookup/Build the IPv4 and IPv6 reverse DNS (PTR) names for an IP address.
TOML Validator
/tools/toml-validator/Validate TOML syntax: structure, comments, key/value errors and duplicate keys.
IDN Converter
/tools/idn-converter/Convert internationalized domain names between Unicode and ASCII (punycode) forms.
IPv6 Expander
/tools/ipv6-expander/Expand a compressed IPv6 address to its full 8-group form and report its canonical form.
URL Query Remover
/tools/url-query-remover/Remove tracking and other query parameters from a URL and report what changed.
Color Contrast Checker
/tools/color-contrast-checker/Compute the WCAG contrast ratio of two colors and report the AA and AAA pass levels.
Query String Parser
/tools/query-string-parser/Parse a URL query string into decoded key/value pairs and a JSON object.
Related categories
Generators
45 tools
Text
50 tools
Encoding
20 tools
JSON
16 tools
Related tools
Related to tools in Developer, derived from the tool metadata.
Date Calculator
/tools/date-calculator/Age Calculator
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/tools/ip-calculator/Area Converter
/tools/area-converter/IPv4/IPv6 Converter
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Related guides & references
Guides and references covering tools in Developer, derived from the tool and content metadata.
Writing Markup and Data Safely in the Browser
/article/browser-editor-guide/Browser Preview and Sanitization Reference
/article/browser-editor-reference/Crypto and Secret Handling Reference
/article/crypto-algorithms-reference/Generating Secrets and Hashing Passwords Safely
/article/crypto-and-secrets-guide/