Free Online Tools for Developers
Streamline your dev workflow — format JSON, test regex, encode Base64, generate UUIDs, decode JWTs, parse cron expressions, format SQL, and more. All in your browser.
No sign-up · No data sent to servers · Instant results
Sponsored · We may earn a commission at no cost to you
Macro Calculator
Calculate daily protein, carbs, and fat needs for your fitness goal
Use tool →JSON to CSV Converter
Convert between JSON and CSV formats
Use tool →YAML/JSON Converter
Convert between YAML and JSON formats
Use tool →Base64 Encoder/Decoder
Encode and decode Base64 strings
Use tool →Cron Expression Builder
Build and explain cron expressions visually
Use tool →Cron Expression Generator
Build and test cron expressions visually with human-readable descriptions and next run times
Use tool →JSON Formatter
Format, validate, and beautify JSON data
Use tool →JWT Decoder
Decode and inspect JSON Web Tokens
Use tool →Regex Tester
Test and debug regular expressions in real-time
Use tool →SQL Formatter
Format and beautify SQL queries
Use tool →Hashtag Generator
Generate relevant hashtags for Instagram, TikTok, and Twitter to boost engagement
Use tool →UUID Generator
Generate unique UUIDs and GUIDs
Use tool →Hash Generator
Generate MD5, SHA-1, SHA-256, and other hashes
Use tool →Frequently Asked Questions
What developer tools does NexTool offer?▾
NexTool offers 30+ free developer tools including JSON formatter, regex tester, Base64 encoder/decoder, UUID generator, hash generator, cron expression parser, SQL formatter, JWT decoder, YAML converter, and many more.
Is my code safe when using these tools?▾
Yes. All developer tools process data entirely in your browser using client-side JavaScript. Your code, tokens, API keys, and data never leave your device. There is zero server-side processing.
Can I use these tools for production debugging?▾
Absolutely. NexTool developer tools handle real-world inputs and edge cases. They are built for daily use by professional developers for formatting, decoding, testing, and debugging tasks.
Explore Tools for Other Audiences
For Freelancers
Essential calculators and tools for freelancers — estimate income tax, convert hourly rates to annual salary, generate invoices, and calculate profit margins. All free, no sign-up required.
10 toolsFor Accountants
Professional-grade calculators for accountants — compute taxes, payroll, profit margins, depreciation schedules, and amortization tables. Instant results, completely free.
23 toolsFor Students
Must-have tools for students — calculate your GPA, estimate student loan payments, convert grades, and crunch percentages. All free and works on any device.
19 toolsFor Retirees
Plan your retirement with confidence — calculate 401(k) growth, estimate annuity income, project Social Security benefits, and analyze pension payouts. All free and private.
8 toolsFor Homebuyers
Navigate home buying with the right numbers — calculate mortgage payments, estimate closing costs, compare renting vs. buying, and assess property taxes. Free and instant.
17 toolsFor Investors
Sharpen your investment strategy — calculate compound interest, analyze ROI, project stock returns, model dollar-cost averaging, and estimate dividend income. All free.
16 toolsFor Entrepreneurs
Launch and grow your business with the right data — calculate startup costs, project revenue, analyze profit margins, model SaaS metrics, and plan funding rounds. All free.
22 toolsFor Fitness Enthusiasts
Optimize your fitness journey — calculate BMI, track calories and macros, estimate protein needs, measure body fat, find target heart rate zones, and pace your runs.
9 toolsFor Teachers
Simplify grading and classroom math — calculate GPAs, convert grades, compute percentages, and run statistics. Fast, free, and works on any device.
7 toolsFor Parents
Helpful tools for every stage of parenting — track pregnancy milestones, estimate ovulation dates, plan college savings, and more. Free, private, and easy to use.
7 toolsFor Small Business Owners
Run your business by the numbers — calculate payroll, generate invoices, analyze profit margins, estimate taxes, compare loan options, and track employee costs. All free.
46 tools