CalcaTools
handyman Tools

Developer Tools

Free online developer tools — JSON formatter, SQL formatter, Base64 encoder/decoder, URL encoder/decoder, hash generator, UUID generator, timestamp converter, schema-markup generator, IP subnet calculator, bandwidth calculator and more.

bug_report

AI Code Explainer | Explain code and suggest fixes

Paste any code and get a plain-English explanation of what each part does, plus likely bugs and edge cases to check. The learning companion for reading unfamiliar code faster.

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schedule

AI Cron Expression Generator | Translate schedules to cron

Describe a schedule in plain English — 'every weekday at 9 AM' — and get a valid five-field cron expression with the syntax explained. Schedule jobs correctly without memorizing cron format.

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commit

AI Git Commit Generator | Generate Conventional Commit messages

Describe what you changed and get a conventional-commit message — summary and body formatted to standard length rules. Write better commit history in seconds, without reading the diff aloud.

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code

AI JSON Extractor | Extract structured JSON from text or data

Extract structured JSON from unstructured text — emails, invoices, product descriptions — by describing the fields you need. Turn free-form documents into clean, parseable data in one step.

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code

AI Regex Generator | Build regular expressions from examples

Describe the text pattern you need in plain English and get a working regular expression with a built-in tester. Build and validate regex for dates, emails and formats without memorizing syntax.

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speed

Bandwidth Calculator | Estimate Transfer Time and Speed

Calculates how long it takes to download or upload a file. Enter the file size and your connection speed in Mbps, and the tool returns the transfer time using time = (file size in MB × 8) ÷ speed, and converts the result into seconds, minutes, and hours. It also converts between Mbps and MB/s.

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enhanced_encryption

Hash Generator | Generate MD5, SHA-1, SHA-256, SHA-512 locally

Compute MD5, SHA-1, SHA-256 and SHA-512 hashes of any text or file directly in your browser, with all four digests shown. Verify file integrity and check data — nothing is uploaded.

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router

IP Subnet Calculator | Show Mask, Network, Hosts, and Broadcast

Breaks an IP address and CIDR prefix into its full subnet details. Enter an address like 192.168.1.0/24, and the tool returns the subnet mask, wildcard mask, network address, broadcast address, usable host range, and total host count. A quick reference for network setup and firewall rules.

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data_object

JSON Formatter | Format, Validate, and Minify JSON Locally

Beautify, minify and validate JSON instantly, with the exact line of any syntax error flagged. Paste messy API responses and get clean, indented, copy-ready JSON in one click — the developer's everyday helper.

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code

Schema Markup Generator | Generate JSON-LD structured data

Generate JSON-LD structured data for SEO — Article, FAQ, LocalBusiness, Product and more — with the correct schema.org properties applied and copyable output. Help search engines understand your pages and qualify for rich results, with the markup validated before you paste it.

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search

SERP Preview | Preview Google search title and meta description

Preview exactly how your page's title and meta description appear in Google search results, with the pixel-based truncation shown. Optimize your title tag and description before publishing — the SEO quick-check.

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database

SQL Formatter | Format and Beautify Raw SQL Queries

Format raw SQL queries into clean, readable, indented code with keywords capitalized and clauses aligned. Supports SELECT, INSERT, UPDATE, DELETE and CREATE statements, and reformatting never changes the query's meaning — the essential tool for debugging and sharing database code.

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schedule

Timestamp Converter | Convert Unix Epoch to Readable Dates

Convert Unix timestamps to human-readable dates and back, in seconds or milliseconds, with UTC and your local time shown. The developer's essential tool for debugging APIs, logs and databases.

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link

URL Encode Decode | Percent-Encode or Decode Text for URLs

Encode and decode URLs and query strings with RFC 3986 percent-encoding, showing each unsafe character converted. Essential for developers building links, API calls and forms with special characters.

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fingerprint

UUID Generator | Generate Secure Version 4 UUIDs Up to 100

Generate version 4 UUIDs — or time-ordered v7 — instantly with a cryptographically secure source, in bulk up to 100 at a time. Valid RFC 4122 format, copied with one click for databases and APIs.

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