Free Online Developer Tools & Utilities

Validate against schemas and estimate JSON payload sizes.

Extract paths, apply RFC 6902 patches, and merge JSON documents.

Compare semantic versions and suggest the next bump level.

Validate Compose files and parse container image references.

Lint nginx configs and build CORS response headers.

Parse .env files and convert Postman environments to dotenv format.

Gitignore templates, branch naming, conventional commits, and release notes.

Inspect PEM blocks, SSH fingerprints, X.509 certs, CSRs, and SSL payloads.

Ports, latency, IP/MAC formatting, IPv6 compression, and subnet host counts.

Humanize uptime, MTTR, error budgets, deployment windows, and SLA percentages.

Validate INI, YAML, TOML, CI pipelines, Makefiles, and Kubernetes names.

Pretty-print JSON log lines and filter by severity level.

Humanize cron expressions and suggest systemd OnCalendar values.

Build Prometheus label matchers and Alertmanager label YAML.

Compute MD5, SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512 digests.

Compare hashes safely, identify algorithms, and constant-time string compare.

Generate secure passwords, memorable passphrases, and numeric PINs.

Check password strength, estimate entropy, and mask secrets in text.

Generate API keys and random cryptographic salt bytes.

Percent-encode and decode URL query strings.

Encode text to hexadecimal and decode hex bytes to UTF-8.

Encode and decode HTML entities for safe markup embedding.

Encode and decode Base64 text in the browser.

Redact secrets and scrub PII patterns from logs and text.

Derive keys from passwords and salt using PBKDF2.

Encrypt and decrypt text with AES-GCM using a passphrase.

Build unsigned JWTs and inspect header and expiry claims.

Validate Luhn numbers, IBANs, and email address formats.

Test XPath-like paths on XML and CSS selectors on HTML snippets.

cURL to fetch, status codes, headers, content types, and MIME lookup.

Build and parse URL query strings from key-value pairs.

Mock JSON, fake emails, random strings, and seeded UUIDs for testing.

Regex replace, assertion formatting, snapshot normalization, and test IDs.

Build Playwright locators and lint Gherkin feature files.

Validate OpenAPI paths and build REST URL segments.

Summarize HAR archives and validate SOAP envelope structure.

Bug report templates, test outlines, boundary values, equivalence classes, and mock delays.

Extract browser and OS hints from User-Agent strings.

Unix timestamps, epoch milliseconds, ISO validation, date diffs, age, and timezones.

Convert hex/RGB colors, number bases, and Roman numerals.

Percentages, GCD/LCM, primes, Fibonacci sequences, and safe expression eval.

View UTF-8 as binary and convert between text and byte strings.

UUID v4, NanoID, random integers, and lorem ipsum placeholder text.

Convert bytes, bandwidth, temperature, length, and GPS coordinates.

Translate text to Morse code and decode Morse back to text.

Verify Stripe, GitHub, Slack, and generic HMAC webhook signatures in the browser.

Parse nginx and Apache combined access log lines into structured JSON fields.

Validate full OpenAPI 3.x or Swagger 2.x documents for required fields and structure.

Generate QR codes from URLs or text entirely in the browser.

Live Markdown preview with headings, lists, and inline formatting.

Merge and diff Helm values YAML files for chart overrides.

Parse JSON log lines, filter by severity, and extract distributed trace IDs.

Parse URLs and build campaign links with UTM query parameters.

Generate Ed25519 key pairs and compute SSH public key fingerprints.

Validate docker-compose.yml structure and service definitions before deploy.

Decode JWT tokens and inspect header, payload, and signature.

Calculate the next 5 run times from a cron expression.

Validate Kubernetes manifest YAML for syntax and structure.

Convert between JSON, YAML, TOML, and XML instantly.

Format messy SQL queries with proper indentation.

Decompress base64-encoded gzip data in the browser.

Analyze IPv4 CIDR blocks, subnets, and host ranges.

Generate RSA key pairs locally using Web Crypto.

Verify plaintext passwords against bcrypt hashes.

Test regex patterns with real-time match highlighting.

Check Dockerfiles against best-practice rules.

Visualize IAM policy statements and permissions.

Estimate system throughput from latency and concurrency.

Compute HMAC-SHA256 signatures for webhook testing.

Bulk-generate UUID v4 or NanoID strings.