Articles, tutorials, and updates about developer tools and productivity.
Everything about JSON formatting: pretty-print vs minify, indentation standards, JSON5 and JSONC comments, common validation errors, sorting keys, and programmatic examples in JS and Python.
Learn how diff tools work: Myers algorithm, unified vs side-by-side output, line vs word vs character diff, YAML comparison, and practical use cases for config auditing, PR review, and debugging.
Learn how to resize images correctly: pixels vs percentage, aspect ratio locking, DPI vs PPI for print and screen, why upscaling degrades quality, and practical tips for web developers.
Learn how QR codes work: data types they encode, error correction levels (L/M/Q/H), size and format tradeoffs, and practical use cases — URLs, vCards, WiFi credentials, and 2FA setup.
The 20 git recipes that solve 95% of real problems. Reset vs revert, merge vs rebase, reflog recovery, safe force-push, bisect, interactive rebase, plus aliases worth setting.
Learn what makes a password strong: entropy math, NIST 2024 guidelines, passphrases vs random strings, CSPRNG code for Node/Python/browser, and why Math.random fails for passwords.
Choose the right image format: PNG vs JPEG vs WebP vs AVIF tradeoffs, lossy vs lossless, transparency, browser compatibility matrix, and conversion workflows with sharp and squoosh.
Master image compression: lossy vs lossless mechanics, JPEG/PNG/WebP/AVIF internals, quality thresholds, file size targets per use case, and LCP impact for web performance.
Pick the right color model: RGB and hex, HSL, HSV vs HSL, OKLCH for perceptually uniform design, sRGB vs P3 gamuts, CSS custom properties, and design token workflows.
UUID versions compared: why v7 beats v4 for database indexes, ULID comparison, collision probability math, RFC 9562 changes, and code for Node/Python/Postgres/Rust.
Format SQL consistently: keyword casing, CTE layout, JOIN formatting, MySQL vs PostgreSQL vs SQLite dialect notes, sqlfluff in CI, and pre-commit hooks.
Convert Markdown to HTML correctly: CommonMark vs GFM vs MDX differences, HTML sanitization against XSS, parser ecosystem (markdown-it, remark), and email rendering pipelines.
Convert HTML to JSX: attribute renames (className, htmlFor), style objects, self-closing tags, event handlers, SVG conversion, and when to use dangerouslySetInnerHTML.
Translate curl commands to code: flag anatomy, mapping to JS fetch / Python requests / axios / Go, cookie handling, auth patterns, and multipart uploads with working examples.
Generate TypeScript from JSON: how Quicktype infers types, nullable vs optional fields, recursive types, Go/Python/Rust targets, and adding runtime validation with Zod.
Verify webhook signatures with HMAC: Stripe-Signature and X-Hub-Signature-256 formats, timing-safe comparison, replay protection with timestamps, and key rotation strategies.
How TOTP authenticator apps work: RFC 6238 + RFC 4226, HMAC-SHA1 truncation, 30-second windows, Base32 secrets, otpauth URI format, and backup codes best practices.
Generate and store RSA keys correctly: 2048 vs 4096 sizes, PEM vs DER vs JWK formats, PKCS#1 vs PKCS#8, RSA vs ECDSA vs Ed25519, and SSH key workflow.
Hash passwords with bcrypt: why SHA-256 is wrong for passwords, cost factor math, built-in salting, 72-byte truncation, bcrypt vs Argon2 vs scrypt, and upgrading cost over time.
YAML vs TOML compared: syntax philosophies, multiline strings, arrays of tables, implicit type gotchas (the Norway NO problem), and when each format wins.
Validate IBANs correctly: structure (country code + check digits + BBAN), mod-97 algorithm step by step, country-specific lengths, and payment form UX best practices.
Parse URLs correctly: RFC 3986 components, encoding rules per component, JavaScript URL API, IDN/Punycode, and common bugs like double-encoding and fragment stripping.
Parse user-agent strings in 2026: why UA sniffing is unreliable, UA reduction initiative, Client Hints (Sec-CH-UA), bot detection, and legitimate parsing libraries.
Validate JSON with JSON Schema: draft-07 vs 2020-12 differences, core keywords, $ref and $defs, conditional validation, OpenAPI relationship, and ajv/zod/valibot tooling.
Understand Base58: Bitcoin's alphabet choice, Base58Check checksumming, IPFS CID format, size comparison with Base64, and when to pick Base58 over other encodings.
Hex and ASCII essentials: byte-to-hex mapping, reading hexdump/xxd output, debugging network payloads, crypto hex outputs, and UTF-8 multi-byte sequences.
Why 1 TB shows as 931 GiB: IEC binary vs SI decimal prefixes, bits vs bytes in network bandwidth, formatting helpers, and platform differences (Windows vs macOS).
Master IPv4 subnetting: CIDR notation, prefix length math, network vs broadcast addresses, VLSM, RFC 1918 ranges, and AWS VPC / Kubernetes / Docker sizing patterns.
IPv6 essentials for app code: 128-bit addresses, :: shortening, global vs link-local scopes, /64 subnetting, URL bracket syntax, and dual-stack socket patterns.
Escape strings for every context: JSON backslash sequences, HTML entities, URL percent-encoding, SQL quotes, shell quoting, regex metachars, and cross-context bugs.
Line manipulation for developers: sort strategies (locale-aware, numeric, version), deduplication (case, whitespace, Unicode), empty line removal, and CLI equivalents.
Master regex replace: capture groups, backreferences ($1, \1), greedy vs non-greedy, multiline mode, case preservation, and ReDoS pitfalls across JS/Python/sed.
Generate fake test data that doesn't break tests: seeded randomness, locale-aware Faker, realistic vs predictable tradeoffs, and MSW/Playwright integration patterns.
Letterbox, pillarbox, and windowbox explained: CSS object-fit values, sharp server-side boxing, canvas padding, and social media aspect ratios (1:1, 4:5, 9:16, 16:9).
OPML file format for RSS reader interop: structure, extraction with XPath/DOMParser, Feedly/Inoreader/NetNewsWire compatibility, and programmatic feed URL discovery.
Compare .docx files reliably: docx is a ZIP of XML, byte vs structural vs semantic comparison, Word's built-in Compare limitations, and pandoc-to-markdown diff workflows.
Roman numerals explained: I/V/X/L/C/D/M symbols, additive and subtractive rules, the 3999 ceiling, MCMLXXXIV decoded, and working JS/Python converters.
Why "Password1!" is weak: entropy math, hardware crack rates, zxcvbn scoring, NIST 2024 guidance against forced complexity, and Have I Been Pwned breach checking.
HTTP status codes for REST APIs: all five classes, 422 vs 400 validation, 401 vs 403, retry-safe codes (408, 429, 503), and common anti-patterns to avoid.
Set Content-Type correctly: MIME anatomy, top-level types, charset parameters, vendor types (application/vnd.*), MIME sniffing risks, and X-Content-Type-Options: nosniff.
Mermaid syntax for every diagram type: flowcharts, sequence diagrams, class diagrams, ER diagrams, rendering on GitHub/GitLab/Notion, and mmdc CLI for docs-as-code.
Write meta tags that actually work: Open Graph for Facebook/LinkedIn, Twitter Cards, og:image (1200×630), JSON-LD structured data, and dynamic OG images with @vercel/og.
Format Python code consistently: Black vs ruff format vs autopep8, line length debates, pyproject.toml config, pre-commit integration, and CI enforcement.
Build color palettes that work: harmony rules, k-means extraction from images, design system scales in OKLCH, tints and shades, and WCAG contrast checks.
Convert docker run commands to compose: flag-to-field mapping (-p, -v, -e, --restart), bind mounts vs named volumes, override files, and Compose v2 vs v1.
Format SCSS consistently: Prettier config, stylelint stylistic vs logic rules, nesting depth limits, @use/@forward replacing @import, and pre-commit integration.
Handle keyboard events correctly: event.key vs event.code, deprecated keyCode, cross-platform modifiers (Cmd/Ctrl), shortcut libraries, and international keyboard pitfalls.
Parse phone numbers correctly: E.164 format, why regex validation fails internationally, libphonenumber usage, display vs storage formats, and extension handling.
Generate SEO-friendly URL slugs: Unicode NFD normalization, transliteration beyond Latin, stop-word tradeoffs, collision handling, and slug-vs-ID URL patterns.
Base32 encoding explained: RFC 4648 alphabet, Crockford variant (excludes I/L/O/U), z-base-32, why TOTP uses Base32, padding rules, and size overhead vs Base64.
Generate ASCII art for CLIs and READMEs: Figlet fonts, width constraints, Unicode box-drawing characters, and programmatic generation with figlet/pyfiglet.
MAC address structure: OUI + NIC split, I/G and U/L bits, well-known prefixes (Docker, VMware), privacy randomization in modern OSes, and generating valid random MACs.
Apply Shannon entropy: formula explained, English text entropy, file entropy for malware detection, password entropy vs strength, and sliding-window analysis.
scrypt for password hashing: memory-hard design vs bcrypt, N/r/p parameter tuning, scrypt vs Argon2id vs bcrypt, OWASP ranking, and code for Node/Python/Rust.
Decode Protocol Buffers: wire format, varint encoding, length-delimited fields, schemaless vs schema-aware decoding, gRPC framing, and protoc/grpcurl tools.
BIP-39 seed phrases explained: 2048-word list, entropy + checksum encoding, 12 vs 24 words, PBKDF2 seed derivation, 25th-word passphrase, and BIP-44 derivation paths.
Extract URLs, emails, IPs, and UUIDs from text: regex patterns, RFC 5322 email gotchas, IDN/Punycode handling, dedup/normalization, and tldextract for domain work.
Why security teams write hxxp:// and [.]com: defanging conventions, preventing accidental clicks, refanging for analysis, STIX/MISP integration, and defang/refang code.
Complete regex reference: quantifiers, character classes, anchors, groups, lookahead, lookbehind, named captures, flags, and 20+ ready-to-use patterns for email, URL, IP, date, and more.
Developers routinely paste JWT tokens, API keys, passwords, and database credentials into online tools that send them to servers. Learn why client-side processing matters and how to verify it yourself.
Master Linux file permissions: understand octal notation (755, 644, 777), symbolic mode (u+x, g-w), owner/group/others, special bits (setuid, sticky), and common real-world permission patterns.
Learn how JWT tokens work: decode the header and payload with Base64url, read standard claims (sub, exp, iat, iss), verify signatures, and debug tokens safely — with JavaScript and Node.js examples.
Transform your browser's new tab into a powerful developer tools hub with DevToys New Tab extension. Access essential dev tools instantly - JSON formatter, Base64 encoder, Hash generator, UUID, JWT decoder & more.
DevToys Web Pro is a modern collection of free online developer tools for formatting JSON, comparing text, testing regex, encoding Base64, generating UUIDs, and more — all in your browser.
Discover how DevToys Web Pro brings 32 essential developer tools into one fast, accessible platform for converters, encoders, formatters, generators, and more.
Master list operations: compare two lists, find duplicates, identify unique items, and perform set operations (union, intersection, difference). Practical guide with examples for developers.
Master number base conversion between hexadecimal, binary, octal, and decimal. Learn hex color codes, bitwise operations, memory addresses, and practical conversion techniques with examples.
Compare MD5, SHA-1, SHA-256, SHA-512, and BLAKE2 hashing algorithms. Learn speed vs security tradeoffs, when to use each algorithm, deprecated algorithms, and performance benchmarks for file integrity.
Learn when to use client-side vs server-side processing for file operations. Understand file size limits, privacy considerations, performance tradeoffs, and enterprise tools vs browser limitations.
Learn Quoted-Printable encoding for emails: MIME encoding rules, soft line breaks, when to use QP vs Base64, email compatibility. Practical guide with real examples for developers.
Learn when HTML entity encoding is required for security. Understand XSS prevention, JSON in HTML, attribute vs text encoding, and when escaping is optional. Practical guide with real examples.
Deep dive into URL encoding edge cases: space vs plus, percent encoding, and application/x-www-form-urlencoded vs RFC 3986. Learn how to debug broken query strings with practical examples.
Master image optimization with this comprehensive guide. Learn format selection (JPEG, PNG, WebP, AVIF), compression strategies, quality vs file size tradeoffs, and performance impact for web development.
Learn to design accessible interfaces for color blind users: understand protanopia, deuteranopia, and tritanopia, use color blindness simulators, create accessible palettes, and avoid common design mistakes.
Master WCAG color contrast requirements: understand AA (4.5:1) and AAA (7:1) ratios, test accessibility with contrast checkers, fix common failures, and design inclusive interfaces for all users.
Learn advanced GZip compression settings: compression levels (1-9), Deflate vs Zlib formats, streaming compression, and when to use server-side processing for optimal performance and file size.
Learn when to use server-side hash calculation for large files, bulk operations, and enterprise workflows. Understand MD5, SHA-256, SHA-512, and BLAKE2 performance for file integrity verification.
Learn about AVIF and HEIF image formats: compression efficiency, browser support, conversion workflows, and when to use modern image formats over JPEG and PNG for web performance.
Learn enterprise XML schema validation with XSD. Understand namespace handling, schema compliance, batch validation, and how to validate XML against XSD schemas for APIs and configurations.
Discover DevToys Web - a complete suite of free web developer tools accessible directly in your browser. 30+ utilities including JSON formatter, Base64 encoder, UUID generator, regex tester & more. No installation, works offline, privacy-focused.
Dev Toys is a swiss army knife for developers — 30+ free tools for formatting JSON, comparing text, testing regexp, encoding data, and more. No installation, runs in your browser, works offline.
Complete web data encoding workflow: URL encoding for query parameters, HTML entity escaping for display, and Quoted-Printable for email. Practical guide for web developers handling special characters.
Complete configuration management workflow: convert between YAML and JSON formats, validate syntax, and compare configuration versions to track changes. Practical guide for DevOps and developers.
Step-by-step workflow for debugging APIs: format messy JSON responses, extract data with JSONPath queries, and export results to CSV for analysis. Practical guide with real API examples.
Learn why JSON parsers reject trailing commas and comments, how to identify non-standard JSON in the wild, and common parsing issues when working with configuration files and APIs.
Learn the critical differences between hashing (MD5, SHA256), encryption, and password hashing. Understand when to use each, common mistakes, and best practices for file integrity and security.
Learn practical Base64 usage: data URLs for images, MIME type prefixes, embedding files in HTML/CSS, PDF encoding, and debugging common Base64 decode errors.
Learn how XML converts to JSON and back. Understand attribute mapping, text content (#text), array detection, namespaces, and how to predict XML↔JSON conversion output.
Learn about YAML implicit type conversion pitfalls. Understand how YAML parsers interpret yes/no, null values, leading zeros, and when to use quotes to prevent unexpected type coercion.
Learn the difference between well-formed XML and schema-valid XML. Understand what XML validators check, common validation errors, and how to validate XML against XSD schemas.
Learn how to decode X.509 certificates: Subject Alternative Names, Extended Key Usage, fingerprints, PEM vs DER formats. Understand certificate fields and validate SSL/TLS certificates.
Learn the differences between GZip, Deflate, and Zlib compression formats. Understand format headers, when tools fail, and how to choose the right compression format for your data.
Debug timestamp conversion issues between seconds and milliseconds. Learn Unix timestamp formats, timezone handling, and common pitfalls when working with epoch time in APIs.
Learn why JSON to CSV conversions often produce unexpected results. Covers nested objects, arrays, missing headers, and flattening strategies with practical solutions.
Complete JSONPath reference guide for API debugging: operators, filter expressions, array operations, and real-world query scenarios. Learn $.store.book[*], recursive descent, and advanced filtering.
Master cron syntax with practical examples: translate between human-readable schedules and cron expressions. Learn cron fields, wildcards, ranges, steps, and common patterns for backups, CI/CD, and automation.
Deep dive into regex newline handling: DotAll (s flag), Multiline (m flag), anchors, and common pitfalls. Learn pattern matching across lines, cross-language differences, and practical multiline regex patterns.
Essential guide to JSON string escaping: escape sequences, nested JSON, debugging double-encoded strings, and handling special characters. Fix common JSON syntax errors with practical examples.
Technical guide to essential data converters: JSON to YAML, XML to JSON, cron expression parser, timestamp converter, number base converter. Practical examples for real development workflows.
Technical guide to Base64 encoding, JWT decoding, URL encoding, HTML entities, GZip compression, certificate decoding, and QR codes. Practical examples for API debugging and data handling.
Technical guide to code formatting: JSON beautifier and minifier, SQL query formatter, XML prettifier. Best practices for formatting JSON, debugging minified code, and improving readability.
Technical guide to generators: UUID v1/v4/v6/v7, secure password generation, MD5/SHA256 hash checksums, and Lorem Ipsum. Practical examples for testing, security, and data integrity.
Technical guide to text tools: diff text comparison, list comparer, text analyzer, case converter, Markdown preview, and string escape utilities. Practical examples for code reviews and debugging.
Technical guide to testing tools: regex tester for pattern matching, JSONPath evaluator for JSON queries, XML validator for syntax checking. Practical examples with regex new line, multiline patterns, and more.
Technical guide to image tools: image compressor, resizer, format converter, color picker, hex to rgb converter, and color blindness simulator for accessibility testing. Optimize images for web performance.
