Dev & data tools: JSON, UUID, subnet/CIDR, random CSV

Quick guide

Start with Query String Parser or URL Encoder when the job is reading, decoding, and rebuilding raw URLs or query fragments.
Use Base64, JSON Formatter, JSON Diff, and Text Diff together when the next step is comparing payloads or cleaning transport-safe text.
Open Hash Generator, UUID Generator, or Token Generator when the task is integrity checking, identifier creation, or browser-only token generation.
Use the random test-data generators when you need CSV, JSON, SQL, logs, or time series before QA, demos, or fixture-driven development.
When data already exists, inspect it with CSV Column Profiler first, then move to charts or statistics only after the columns and missing values make sense.
Use Subnet CIDR for host ranges and capacity, then keep related networking checks in the same browser session when you are planning IP layouts.
For design-token work, keep the flow compact: format the color, tune the role palette, preview and audit it, then export only after naming and alias checks look stable.
Use Token Counter before you paste prompts, configs, or serialized payloads into another app so you can spot size problems early.

Tools

Base64 Encode / Decode Tool.
Encode text to Base64, decode Base64 to text, and convert files to Base64 or data URI locally in your browser.
JSON Formatter & Validator.
Pretty-print, minify, and validate JSON in your browser.
Query String Parser.
Parse raw query strings or full URLs, inspect repeated keys, decode values, and copy a normalized query locally.
Hash Generator Tool.
Generate SHA-1, SHA-256, and SHA-512 hashes for text or files in your browser.
URL Encoder / Decoder Tool.
Percent-encode text, decode strings, and parse full URLs with an editable query parameter list in your browser.
Float Inspector Tool.
Inspect IEEE 754 bit layouts for float16, bfloat16, float32, and float64.
Regex Tester Tool.
Test JavaScript regular expressions online with pattern, flags, match preview, capture groups, and replace output.
JSON Diff Tool.
Compare two JSON documents online by structure.
Text Diff Tool.
Compare two plain text blocks online line by line.
UUID Generator (v4/v7) – bulk, format, validate.
Generate UUID v4 or UUID v7 in bulk, format them (canonical/URN/braces), copy or download, and validate UUIDs with v7.
IPv4 subnet & CIDR calculator – network address, host.
Convert any IPv4 address and prefix length into its network address, broadcast address, usable host range.
Pattern String Generator — business IDs & sequences.
Generate business-style IDs from a pattern (date, sequence, random).
Random JSON Generator (Test Data) — array & NDJSON.
Generate JSON test data from a schema. Export as JSON array or NDJSON.
Random SQL INSERT Generator — Postgres, MySQL, SQLite.
Generate SQL INSERT statements from a schema for Postgres, MySQL, or SQLite.
Random Log Generator — Nginx, Apache & JSON logs.
Generate fake access logs (Nginx/Apache) or JSONL logs with controllable distributions.
Synthetic Time Series Generator — trend, seasonality.
Generate synthetic time series data with trend, seasonality, noise, missing values, and outliers.
Random CSV generator – test data & schema JSON.
Generate random CSV test data in your browser.
CSV Column Profiler.
Paste CSV or TSV data to inspect column types, missing values, unique counts, and next chart or stats options.
Token generator – secure random strings (base64url, hex).
Generate secure random tokens and random strings locally in your browser.
Embed Builder — share links & iframe code.
Create CalcBE share links and responsive iframe embeds.
Text Case Converter — upper/lower/title.
Convert text between upper, lower, title, sentence, snake_case, camelCase, and kebab-case instantly in your browser.
Zenkaku/Hankaku Converter – kana, fullwidth/halfwidth.
Convert Japanese text between fullwidth/halfwidth and Hiragana/Katakana in your browser.

Calculators

Base Converter & Bitwise Toolkit (Bin/Oct/Dec/Hex).
Convert between binary, octal, decimal, and hexadecimal, and run AND/OR/XOR/NOT and bit shifts—then copy.

Data visualization: quick charts, histograms, regression | CalcBE
Move here when the next step is profiling a dataset, charting it quickly, or checking descriptive statistics before handoff.
Random & Lotteries: Pickers, Dice, Probability | CalcBE
Open random tools when you need browser-only fixture data, seeded draws, or reusable test inputs for QA and demos.
PDF tools (compress, merge, split) — browser-only | CalcBE
Switch to PDF tools when the data prep work is done and the next deliverable is a browser-only export or document cleanup.
Date & Time Calculators: Days Between, Business Days | CalcBE
Use date and time pages when logs, schedules, or fixtures depend on business days, windows, or recurring intervals.
Statistics & probability calculators | CalcBE
Open statistics pages when the next task after cleanup is sampling, grouped frequencies, or probability checks rather than raw data prep.

Quick guide

Tools

Calculators

Related categories