Tools for developers
and crypto users
Free online tools for developers and crypto users. Unit converters, JSON formatter, ETH gas tracker, crypto P&L calculator and more.
Featured tools
Password Generator
Generate strong, secure random passwords instantly.
Private JSON Formatter & Validator
Format and validate JSON securely offline in your browser. 100% local—no data sent to servers.
Code Diff Checker
Compare two blocks of text or code and highlight differences.
Regex Tester
Test regular expressions with live match highlighting and saved patterns.
JWT Decoder
Decode and inspect JWT tokens — header, payload and expiry.
ETH Gas Tracker
Live Ethereum gas prices — slow, standard and fast.
Crypto P&L Calculator
Calculate your crypto profit and loss from any trade.
Wallet Age Checker
Check how old any Ethereum wallet address is.
Crypto Portfolio Tracker
Track your crypto holdings with live prices and P&L.
Crypto Watchlist
Watch live crypto prices with custom target alerts.
DCA Calculator
Calculate returns from dollar cost averaging into any crypto.
Budget Tracker
Track income and expenses by category with monthly overview.
Net Worth Tracker
Track assets and liabilities to calculate and monitor your net worth.
Compound Interest Calculator
See how investments grow over time with compound interest.
Pomodoro Timer
Focus timer with 25/5 sessions, streaks and daily history.
Todo List
Clean todo list with priorities, due dates and local storage.
Quick Notes
Instant notes with multiple tabs, auto-save and markdown support.
Habit Tracker
Track daily habits with streaks, heatmap and completion history.
QR Code Generator
Generate and scan QR codes for URLs, text, WiFi and more.
CSV ↔ JSON Converter
Convert CSV to JSON and JSON to CSV with live preview.
Code Snippet Manager
Save, organize and search code snippets with syntax highlighting.
Markdown Editor
Full markdown editor with live preview and document library.
Resume / CV Builder
Build a professional resume and export as PDF — free, no watermark.
Kanban Board
Drag-and-drop Kanban board saved entirely in your browser.
Smart Contract Reader
Interact with any smart contract using its ABI — no coding needed.
Solana Transaction Decoder
Decode any Solana transaction into human-readable instructions.
Multi-Wallet Balance Checker
Check token balances across multiple wallets in one view.
Image Compressor
Compress images to reduce file size without losing quality.
Image Resizer
Resize images to exact dimensions or by percentage.
Image Cropper
Crop images with freeform or fixed aspect ratio selection.
Image Format Converter
Convert images between JPG, PNG, WebP and GIF formats.
Color Picker from Image
Pick any color from an uploaded image and get HEX, RGB and HSL values.
Favicon Generator
Generate favicon.ico and PNG icons in all sizes from any image.
Image Filters & Effects
Apply filters to images — brightness, contrast, blur, grayscale and more.
SVG to PNG Converter
Convert SVG files to PNG at any resolution.
PDF to Images
Convert PDF pages to PNG or JPG images.
PDF Merger
Combine multiple PDF files into one.
PDF Splitter
Split a PDF into individual pages or page ranges.
PDF Watermark
Add text or image watermarks to PDF pages.
PDF Canvas Builder
Build PDFs from scratch with a drag-and-drop canvas.
Invoice Generator
Create professional invoices and download as PDF.
Markdown to PDF
Convert Markdown text to a styled PDF document.
HTML to PDF
Convert any HTML page or snippet to a PDF document.
Unit Converter
Convert length, weight, temperature, area, volume and more.
Percentage Calculator
Calculate percentages, increases, decreases and ratios instantly.
Word & Character Counter
Count words, characters, sentences and reading time instantly.
Password Generator
Generate strong, secure random passwords instantly.
Private JSON Formatter & Validator
Format and validate JSON securely offline in your browser. 100% local—no data sent to servers.
Base64 Encoder / Decoder
Encode and decode Base64 strings instantly.
Hash Generator
Generate MD5, SHA-1, SHA-256 and SHA-512 hashes from any text.
BMI Calculator
Calculate your Body Mass Index and healthy weight range.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and back.
GST / VAT Calculator
Add or remove GST and VAT from any amount instantly.
ROI Calculator
Calculate return on investment for any business or personal investment.
Inflation Calculator
See how inflation erodes purchasing power over time.
Crypto Staking Calculator
Calculate staking rewards and APY returns for any crypto asset.
Liquidation Price Calculator
Calculate liquidation price for leveraged crypto positions.
Code Diff Checker
Compare two blocks of text or code and highlight differences.
Regex Tester
Test regular expressions with live match highlighting and saved patterns.
JWT Decoder
Decode and inspect JWT tokens — header, payload and expiry.
Cron Expression Generator
Build cron expressions visually and see them in plain English.
ETH Gas Tracker
Live Ethereum gas prices — slow, standard and fast.
Crypto P&L Calculator
Calculate your crypto profit and loss from any trade.
Wei / Gwei / ETH Converter
Convert between Wei, Gwei and ETH instantly.
ABI Decoder / Encoder
Decode and encode Ethereum ABI data for smart contracts.
Wallet Age Checker
Check how old any Ethereum wallet address is.
Crypto Tax Estimator
Estimate capital gains tax on your crypto trades.
Crypto Portfolio Tracker
Track your crypto holdings with live prices and P&L.
Crypto Watchlist
Watch live crypto prices with custom target alerts.
DCA Calculator
Calculate returns from dollar cost averaging into any crypto.
Crypto Fear & Greed Index
Live crypto market sentiment — from extreme fear to extreme greed.
Loan / EMI Calculator
Calculate monthly EMI, total interest and repayment schedule.
Budget Tracker
Track income and expenses by category with monthly overview.
Net Worth Tracker
Track assets and liabilities to calculate and monitor your net worth.
Compound Interest Calculator
See how investments grow over time with compound interest.
Pomodoro Timer
Focus timer with 25/5 sessions, streaks and daily history.
Todo List
Clean todo list with priorities, due dates and local storage.
Quick Notes
Instant notes with multiple tabs, auto-save and markdown support.
Habit Tracker
Track daily habits with streaks, heatmap and completion history.
QR Code Generator
Generate and scan QR codes for URLs, text, WiFi and more.
Currency Converter
Live exchange rates for 150+ currencies with favorites.
Typing Speed Test
Test your typing speed in WPM with accuracy tracking and history.
SQL Formatter
Format and beautify SQL queries with dialect support.
CSV ↔ JSON Converter
Convert CSV to JSON and JSON to CSV with live preview.
XML / HTML Formatter
Format, validate and minify XML and HTML with error highlighting.
Code Snippet Manager
Save, organize and search code snippets with syntax highlighting.
Markdown Editor
Full markdown editor with live preview and document library.
Mortgage Calculator
Calculate mortgage payments with amortization chart and scenarios.
Scientific Calculator
Full scientific calculator with formula history and variable support.
Color Palette Generator
Generate harmonious palettes and convert between color formats.
Chart Builder
Build bar, line, pie and scatter charts from CSV data — no signup.
Resume / CV Builder
Build a professional resume and export as PDF — free, no watermark.
Kanban Board
Drag-and-drop Kanban board saved entirely in your browser.
Flashcard Study Tool
Create flashcard decks with spaced repetition and progress tracking.
Smart Contract Reader
Interact with any smart contract using its ABI — no coding needed.
Solana Transaction Decoder
Decode any Solana transaction into human-readable instructions.
Multi-Wallet Balance Checker
Check token balances across multiple wallets in one view.
BIP39 Mnemonic Generator
Generate and validate BIP39 mnemonic seed phrases offline.
Image Compressor
Compress images to reduce file size without losing quality.
Image Resizer
Resize images to exact dimensions or by percentage.
Image Cropper
Crop images with freeform or fixed aspect ratio selection.
Image Format Converter
Convert images between JPG, PNG, WebP and GIF formats.
Image to Base64
Convert images to Base64 strings for use in HTML and CSS.
EXIF Metadata Viewer
View hidden metadata inside photos — camera, GPS, settings.
Color Picker from Image
Pick any color from an uploaded image and get HEX, RGB and HSL values.
Favicon Generator
Generate favicon.ico and PNG icons in all sizes from any image.
Image Filters & Effects
Apply filters to images — brightness, contrast, blur, grayscale and more.
Image Watermark
Add text or image watermarks to your photos.
SVG to PNG Converter
Convert SVG files to PNG at any resolution.
PDF to Images
Convert PDF pages to PNG or JPG images.
Image Diff Checker
Compare two images and highlight pixel differences.
PDF Merger
Combine multiple PDF files into one.
PDF Splitter
Split a PDF into individual pages or page ranges.
PDF Compressor
Reduce PDF file size without losing quality.
PDF to Text Extractor
Extract all text content from any PDF.
PDF Page Rotator
Rotate PDF pages 90, 180 or 270 degrees.
PDF Watermark
Add text or image watermarks to PDF pages.
PDF Metadata Editor
View and edit PDF metadata — title, author, subject and more.
PDF Page Reorder
Drag and drop to reorder pages in a PDF.
PDF Form Filler
Fill in PDF form fields and download the completed form.
PDF Canvas Builder
Build PDFs from scratch with a drag-and-drop canvas.
Invoice Generator
Create professional invoices and download as PDF.
Receipt Generator
Generate professional receipts and download as PDF.
Certificate Generator
Design and generate printable certificates as PDF.
Markdown to PDF
Convert Markdown text to a styled PDF document.
HTML to PDF
Convert any HTML page or snippet to a PDF document.
Barcode Generator
Generate barcodes in CODE128, EAN-13, QR and more formats.
Free online tools — no account required
SolveBar provides 84 free tools for developers, crypto traders and everyday users. Every tool runs in your browser — no data is ever sent to a server.
Blockchain and crypto tools
Check live ETH gas prices, calculate crypto trade profit or loss, convert Wei to Gwei, verify wallet age and estimate crypto taxes — all in one place.