veojson.com

Tool directory

44 focused utilities for developers, IT admins and technical founders. Each one works instantly in the browser — no account required.

Developer & API

JWT Decoder & Verifier

Decode header and payload, inspect claims, check expiry.

/tools/jwt-decoder

Base64 Encoder & Decoder

Encode and decode Base64 with full Unicode support.

/tools/base64-encoder

Regex Tester & Builder

Live match highlighting, capture groups and flags.

/tools/regex-tester

Cron Expression Generator

Build cron syntax and preview the next run times.

/tools/cron-expression-generator

SQL Query Formatter

Turn one-line spaghetti SQL into readable, reviewable queries.

/tools/sql-formatter

URL Encoder & Decoder

Percent-encode or decode URLs and query parameters safely.

/tools/url-encoder

HTML Entity Encoder & Decoder

Escape and unescape HTML entities instantly.

/tools/html-entity-encoder

JSON Path Extractor

Query nested JSON with dot paths and wildcards.

/tools/json-path-extractor

JSON Schema Generator

Turn a sample payload into a validation schema.

/tools/json-schema-generator

UUID Generator

Bulk random v4 and sortable v7 identifiers.

/tools/uuid-generator

Unix Timestamp Converter

Epoch seconds and milliseconds to dates, both directions.

/tools/timestamp-converter

YAML to JSON Converter

YAML and JSON conversion with strict validation.

/tools/yaml-json-converter

cURL Converter

Turn any cURL command into Python, JavaScript or Go.

/tools/curl-converter

Security & Infrastructure

Security Headers Checker

Grade a site's HTTP security headers in seconds.

/tools/security-headers-checker

Password Policy Generator

Generate an IT password policy your auditors will accept.

/tools/password-policy-generator

Hash Generator

SHA-1, SHA-256 and SHA-512 digests in your browser.

/tools/hash-generator

HMAC Generator

Sign payloads with HMAC to test webhook verification.

/tools/hmac-generator

Chmod Permission Calculator

Octal and symbolic Unix permissions, both directions.

/tools/chmod-calculator

IP Subnet Calculator

CIDR to network, broadcast, host range and mask.

/tools/subnet-calculator

Byte Converter

Decimal and binary data size conversion side by side.

/tools/byte-converter

Secure API Key Generator

CSPRNG-backed keys, tokens and secrets with prefixes.

/tools/api-key-generator

Password Strength Checker

Entropy in bits and a realistic offline crack estimate.

/tools/password-strength-checker

DNS Lookup Tool

Live DNS record lookup with TTLs, over DoH.

/tools/dns-lookup

Uptime SLA Calculator

Turn nines into real downtime budgets.

/tools/sla-uptime-calculator

AI & Prompts

AI Cost Calculator

Project monthly LLM spend across models before you ship.

/tools/ai-cost-calculator

Prompt Generator & Optimizer

Turn a rough idea into a structured system prompt.

/tools/prompt-optimizer

LLM Token Counter

Estimate prompt tokens and what they cost per call.

/tools/token-counter

Prompt Template Builder

Assemble structured, reusable prompts section by section.

/tools/prompt-template-builder

Business & Ops

ROI Calculator

ROI, net profit, ROAS and payback period in one view.

/tools/roi-calculator

SaaS Churn & LTV Calculator

LTV, average lifetime and LTV:CAC from MRR and churn.

/tools/churn-ltv-calculator

Freelance Hourly Rate Calculator

The rate you actually need, after tax, expenses and time off.

/tools/freelance-rate-calculator

Word & Character Counter

Words, characters, reading time and SEO length checks.

/tools/word-counter

Profit Margin Calculator

Margin, markup and target-price maths in one place.

/tools/profit-margin-calculator

Break-Even Calculator

Units and revenue needed before you make a profit.

/tools/break-even-calculator

NPS Calculator

Score, breakdown and benchmark from raw survey counts.

/tools/nps-calculator

Utility & Formatting

JSON Formatter & Validator

Beautify, minify and validate JSON with precise error positions.

/tools/json-formatter

JSON to CSV Converter

Convert JSON arrays to CSV and CSV back to JSON.

/tools/json-csv-converter

Text Diff Checker

Line-by-line comparison of two text blocks.

/tools/diff-checker

QR Code Generator

Clean, trackable-free QR codes as downloadable PNGs.

/tools/qr-code-generator

URL Slug Generator

Clean, readable, SEO-friendly URL slugs from any title.

/tools/slug-generator

Case Converter

Switch identifiers between every common naming convention.

/tools/case-converter

Lorem Ipsum Generator

Placeholder copy for mockups, in plain text or HTML.

/tools/lorem-ipsum-generator

Color Converter

HEX, RGB, HSL and OKLCH conversions with live preview.

/tools/color-converter

Markdown to HTML Converter

Markdown in, clean semantic HTML out, with live preview.

/tools/markdown-to-html