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Format JSON, compress images, convert text, run calculations, and solve everyday tasks without sending your data anywhere.
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56+ Tools
Free forever library
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Runs local-first
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No data uploads
Fast & Lightweight
Built for performance
Featured Tools
JSON Formatter
Format, beautify, minify, and validate JSON data instantly with syntax highlighting, error detection, and tree view.
Base64 Encoder & Decoder
Encode text, files, and images to Base64 format. Decode Base64 back to original content. Browser-based with image preview and file upload support.
URL Encoder & Decoder
Encode text to URL-safe format and decode percent-encoded URLs back to readable text. Supports UTF-8, Unicode, and SVG encoding.
JWT Decoder & Local Verifier
Decode and inspect JSON Web Tokens (JWT) entirely in your browser. Verify signatures locally with HS256/384/512, RS256/384/512, or ES256/384/512. Analyze claims, validate expiration times, check for security risks, and simulate clock skew with 100% offline, zero-knowledge privacy.
Markdown Live Editor
Write, edit, and preview Markdown in real time. Export rendered HTML or download your Markdown files. Full GFM support with live preview.
Text Case Converter
Convert text to uppercase, lowercase, sentence case, title case, camelCase, snake_case, PascalCase, kebab-case, and more instantly.
Word Counter
Count words, characters, sentences, paragraphs, and reading time instantly.
Percentage Calculator
Calculate percentages, percentage increases, decreases, differences, and reverse percentages instantly. Free online percentage calculator with step-by-step solutions.
Loan Calculator
Calculate monthly loan payments, total interest, amortization schedules, and payoff timelines.
Simple List A/B Comparator
Compare two lists instantly in your browser. Find shared items, unique items, differences, and duplicates across lists — all locally with no data uploads.
CSV Column Matcher
Fuzzy match two CSV columns online free — reconcile messy datasets with Levenshtein distance. Find near matches, typos, and inconsistencies across CSV columns in your browser with no uploads.
Color Converter
Convert colors between HEX, RGB, HSL, and CMYK formats instantly with a live color preview.
Image Compressor
Compress, resize, and convert JPG, PNG, and WebP images directly in your browser.
Instagram No Crop Tool
Fit full-size photos into Instagram-friendly aspect ratios without cropping. Add padding, solid colors, or blurred backgrounds, and export ready-to-post images.
Character Counter
Count characters with and without spaces, words, sentences, paragraphs, and reading time instantly.
Lorem Ipsum Generator
Generate placeholder text instantly by paragraphs, words, or characters for layouts, mockups, and design work.
Timezone Overlap Tool
Find shared working hours across multiple time zones with a visual timeline. Compare locations, see current local times, and identify the best overlap.
Cursive Generator
Convert normal text into cursive, script, and fancy Unicode styles instantly. Preview signature fonts and copy to clipboard.
Text to Handwriting Converter
Convert digital text into realistic handwritten pages. Choose from multiple handwriting fonts, paper styles, and ink colors. Download as PNG.
Duplicate Line Remover
Remove duplicate lines from text instantly in your browser. Fast, private deduplication for logs, lists, CSVs, and large files — all locally with no uploads.
Email List Deduplicator
Clean, validate, and deduplicate email lists securely in your browser. Remove invalid emails, find duplicates, analyze domains, and export cleaned lists — all locally with no uploads and zero PII exposure.
Domain Name Extractor & Comparator
Extract root domains from URLs and compare two lists instantly in your browser. Parse millions of URLs, normalize domains, strip subdomains, find shared and unique domains — all locally with no uploads.
JSON Array Diff Tool
Compare two JSON arrays or deeply nested objects instantly in your browser with a recursive diff engine. Detect added, removed, and modified keys in API responses, configuration files, and massive enterprise datasets — all locally with zero uploads.
Alphabetical List Sorter
Sort lists alphabetically with intelligent locale-aware sorting in your browser. Handle multilingual datasets, ignore case, sort by length, remove duplicates, and use natural number ordering — all locally with no uploads.
Numeric Tolerance Matcher
Compare two lists of numbers with a margin of error, absolute or percentage tolerance, currency support, and financial reconciliation in your browser — all locally with no uploads.
Multi-List Venn Diagram Generator
Compare 3 lists online to find overlaps, intersections, and unique values. Interactive 3-circle Venn diagram with clickable regions, O(N) set operations, and full export — all in your browser with no uploads.
Text Prefix/Suffix Appender
Add text to the beginning and end of every line instantly. Wrap lists with quotes, commas, HTML tags, SQL formatting, JSON brackets, and more — all in your browser with zero uploads.
Random List Generator & Shuffler
Randomly shuffle any list with cryptographically secure Fisher-Yates shuffle using Web Crypto API. Fair prize draws, unbiased randomization, and bulk list shuffling — all in your browser with zero uploads.
Case-Insensitive Deduplicator
Remove duplicate lines while ignoring letter case. Case-insensitive deduplication preserves the original capitalization of the first occurrence. Fast Set-based processing, Web Worker offloading, and 100% browser-based — no uploads, complete privacy.
Markdown Checkbox List Extractor
Extract checked, unchecked, or all tasks from Markdown documents. Supports Obsidian, Notion, GitHub, GitLab, Logseq exports, and more. Fast regex-based parsing, Web Worker offloading, 100% browser-based — no uploads, complete privacy.
IP Address List Comparator
Compare IPv4, IPv6, and CIDR subnet lists securely with high-performance browser-based processing. Supports mixed IP/CIDR formats, firewall blocklists, and access logs.
OpenPGP Message Encryptor
Encrypt, decrypt, sign, and verify messages using OpenPGP.js in your browser. Supports multi-recipient encryption, digital signatures, ASCII-armored output, and GnuPG-compatible keys with AES-256 and SHA-256.
Secure Password Generator
Generate cryptographically secure passwords using your browser's Web Crypto API. Supports random passwords, memorable passwords, passphrases, PINs, Wi-Fi keys, hex secrets, and Base64 secrets with real-time entropy analysis and bulk generation.
Password Entropy Calculator
Check the mathematical entropy of any password or passphrase in your browser. Uses the Shannon formula L × log₂(R) to measure true password strength, detect weak patterns, estimate crack time, and compare Diceware passphrases — 100% client-side with zero uploads.
Cryptographic Secret Sharing Tool
Split a secret into secure M-of-N recovery shares with real Shamir Secret Sharing, or reconstruct it from the required threshold. Supports BIP39 seed phrases, keys, passwords, Base58/Hex/Base64 shares, QR codes, and offline recovery — entirely in your browser.
Cryptographic Hash Generator
Generate SHA-256, SHA-512, SHA-384, and SHA-1 hashes for files and text locally in your browser. Verify checksums with zero uploads, Web Crypto API support, Web Worker processing, and chunked large-file reading.
Large File Checksum Verifier
Verify file integrity by comparing local files against published MD5, SHA-1, SHA-256, SHA-384, and SHA-512 checksums. Multi-GB support with Web Worker processing, zero uploads, and automatic algorithm detection.
Popular Tools
JSON Formatter
Format, beautify, minify, and validate JSON data instantly with syntax highlighting, error detection, and tree view.
Base64 Encoder & Decoder
Encode text, files, and images to Base64 format. Decode Base64 back to original content. Browser-based with image preview and file upload support.
URL Encoder & Decoder
Encode text to URL-safe format and decode percent-encoded URLs back to readable text. Supports UTF-8, Unicode, and SVG encoding.
JWT Decoder & Local Verifier
Decode and inspect JSON Web Tokens (JWT) entirely in your browser. Verify signatures locally with HS256/384/512, RS256/384/512, or ES256/384/512. Analyze claims, validate expiration times, check for security risks, and simulate clock skew with 100% offline, zero-knowledge privacy.
Markdown Live Editor
Write, edit, and preview Markdown in real time. Export rendered HTML or download your Markdown files. Full GFM support with live preview.
Text Case Converter
Convert text to uppercase, lowercase, sentence case, title case, camelCase, snake_case, PascalCase, kebab-case, and more instantly.
Word Counter
Count words, characters, sentences, paragraphs, and reading time instantly.
Percentage Calculator
Calculate percentages, percentage increases, decreases, differences, and reverse percentages instantly. Free online percentage calculator with step-by-step solutions.
Loan Calculator
Calculate monthly loan payments, total interest, amortization schedules, and payoff timelines.
Simple List A/B Comparator
Compare two lists instantly in your browser. Find shared items, unique items, differences, and duplicates across lists — all locally with no data uploads.
CSV Column Matcher
Fuzzy match two CSV columns online free — reconcile messy datasets with Levenshtein distance. Find near matches, typos, and inconsistencies across CSV columns in your browser with no uploads.
Image Compressor
Compress, resize, and convert JPG, PNG, and WebP images directly in your browser.
SVG Optimizer
Compress and clean up SVG files to optimize loading speed.
Instagram No Crop Tool
Fit full-size photos into Instagram-friendly aspect ratios without cropping. Add padding, solid colors, or blurred backgrounds, and export ready-to-post images.
Character Counter
Count characters with and without spaces, words, sentences, paragraphs, and reading time instantly.
Lorem Ipsum Generator
Generate placeholder text instantly by paragraphs, words, or characters for layouts, mockups, and design work.
Timezone Overlap Tool
Find shared working hours across multiple time zones with a visual timeline. Compare locations, see current local times, and identify the best overlap.
Cursive Generator
Convert normal text into cursive, script, and fancy Unicode styles instantly. Preview signature fonts and copy to clipboard.
Text to Handwriting Converter
Convert digital text into realistic handwritten pages. Choose from multiple handwriting fonts, paper styles, and ink colors. Download as PNG.
Duplicate Line Remover
Remove duplicate lines from text instantly in your browser. Fast, private deduplication for logs, lists, CSVs, and large files — all locally with no uploads.
Email List Deduplicator
Clean, validate, and deduplicate email lists securely in your browser. Remove invalid emails, find duplicates, analyze domains, and export cleaned lists — all locally with no uploads and zero PII exposure.
Domain Name Extractor & Comparator
Extract root domains from URLs and compare two lists instantly in your browser. Parse millions of URLs, normalize domains, strip subdomains, find shared and unique domains — all locally with no uploads.
JSON Array Diff Tool
Compare two JSON arrays or deeply nested objects instantly in your browser with a recursive diff engine. Detect added, removed, and modified keys in API responses, configuration files, and massive enterprise datasets — all locally with zero uploads.
Alphabetical List Sorter
Sort lists alphabetically with intelligent locale-aware sorting in your browser. Handle multilingual datasets, ignore case, sort by length, remove duplicates, and use natural number ordering — all locally with no uploads.
Numeric Tolerance Matcher
Compare two lists of numbers with a margin of error, absolute or percentage tolerance, currency support, and financial reconciliation in your browser — all locally with no uploads.
Multi-List Venn Diagram Generator
Compare 3 lists online to find overlaps, intersections, and unique values. Interactive 3-circle Venn diagram with clickable regions, O(N) set operations, and full export — all in your browser with no uploads.
Text Prefix/Suffix Appender
Add text to the beginning and end of every line instantly. Wrap lists with quotes, commas, HTML tags, SQL formatting, JSON brackets, and more — all in your browser with zero uploads.
Random List Generator & Shuffler
Randomly shuffle any list with cryptographically secure Fisher-Yates shuffle using Web Crypto API. Fair prize draws, unbiased randomization, and bulk list shuffling — all in your browser with zero uploads.
Case-Insensitive Deduplicator
Remove duplicate lines while ignoring letter case. Case-insensitive deduplication preserves the original capitalization of the first occurrence. Fast Set-based processing, Web Worker offloading, and 100% browser-based — no uploads, complete privacy.
Markdown Checkbox List Extractor
Extract checked, unchecked, or all tasks from Markdown documents. Supports Obsidian, Notion, GitHub, GitLab, Logseq exports, and more. Fast regex-based parsing, Web Worker offloading, 100% browser-based — no uploads, complete privacy.
IP Address List Comparator
Compare IPv4, IPv6, and CIDR subnet lists securely with high-performance browser-based processing. Supports mixed IP/CIDR formats, firewall blocklists, and access logs.
OpenPGP Message Encryptor
Encrypt, decrypt, sign, and verify messages using OpenPGP.js in your browser. Supports multi-recipient encryption, digital signatures, ASCII-armored output, and GnuPG-compatible keys with AES-256 and SHA-256.
Secure Password Generator
Generate cryptographically secure passwords using your browser's Web Crypto API. Supports random passwords, memorable passwords, passphrases, PINs, Wi-Fi keys, hex secrets, and Base64 secrets with real-time entropy analysis and bulk generation.
Password Entropy Calculator
Check the mathematical entropy of any password or passphrase in your browser. Uses the Shannon formula L × log₂(R) to measure true password strength, detect weak patterns, estimate crack time, and compare Diceware passphrases — 100% client-side with zero uploads.
Cryptographic Secret Sharing Tool
Split a secret into secure M-of-N recovery shares with real Shamir Secret Sharing, or reconstruct it from the required threshold. Supports BIP39 seed phrases, keys, passwords, Base58/Hex/Base64 shares, QR codes, and offline recovery — entirely in your browser.
Cryptographic Hash Generator
Generate SHA-256, SHA-512, SHA-384, and SHA-1 hashes for files and text locally in your browser. Verify checksums with zero uploads, Web Crypto API support, Web Worker processing, and chunked large-file reading.
Large File Checksum Verifier
Verify file integrity by comparing local files against published MD5, SHA-1, SHA-256, SHA-384, and SHA-512 checksums. Multi-GB support with Web Worker processing, zero uploads, and automatic algorithm detection.
Recently Added Tools
JWT Decoder & Local Verifier
Decode and inspect JSON Web Tokens (JWT) entirely in your browser. Verify signatures locally with HS256/384/512, RS256/384/512, or ES256/384/512. Analyze claims, validate expiration times, check for security risks, and simulate clock skew with 100% offline, zero-knowledge privacy.
Password Entropy Calculator
Check the mathematical entropy of any password or passphrase in your browser. Uses the Shannon formula L × log₂(R) to measure true password strength, detect weak patterns, estimate crack time, and compare Diceware passphrases — 100% client-side with zero uploads.
Cryptographic Secret Sharing Tool
Split a secret into secure M-of-N recovery shares with real Shamir Secret Sharing, or reconstruct it from the required threshold. Supports BIP39 seed phrases, keys, passwords, Base58/Hex/Base64 shares, QR codes, and offline recovery — entirely in your browser.
HKDF Key Derivation Tool
Derive cryptographic keys from a master secret using RFC 5869 HKDF (HMAC-based Key Derivation Function) in your browser. Supports SHA-256, SHA-384, SHA-512, configurable salt, info, and output length. Generate single or multiple derived keys instantly using the native Web Crypto API with zero server interaction.
Cryptographic Hash Generator
Generate SHA-256, SHA-512, SHA-384, and SHA-1 hashes for files and text locally in your browser. Verify checksums with zero uploads, Web Crypto API support, Web Worker processing, and chunked large-file reading.
Large File Checksum Verifier
Verify file integrity by comparing local files against published MD5, SHA-1, SHA-256, SHA-384, and SHA-512 checksums. Multi-GB support with Web Worker processing, zero uploads, and automatic algorithm detection.
Numeric Tolerance Matcher
Compare two lists of numbers with a margin of error, absolute or percentage tolerance, currency support, and financial reconciliation in your browser — all locally with no uploads.
Multi-List Venn Diagram Generator
Compare 3 lists online to find overlaps, intersections, and unique values. Interactive 3-circle Venn diagram with clickable regions, O(N) set operations, and full export — all in your browser with no uploads.
Recently Updated Tools
JWT Decoder & Local Verifier
Decode and inspect JSON Web Tokens (JWT) entirely in your browser. Verify signatures locally with HS256/384/512, RS256/384/512, or ES256/384/512. Analyze claims, validate expiration times, check for security risks, and simulate clock skew with 100% offline, zero-knowledge privacy.
Password Entropy Calculator
Check the mathematical entropy of any password or passphrase in your browser. Uses the Shannon formula L × log₂(R) to measure true password strength, detect weak patterns, estimate crack time, and compare Diceware passphrases — 100% client-side with zero uploads.
Cryptographic Secret Sharing Tool
Split a secret into secure M-of-N recovery shares with real Shamir Secret Sharing, or reconstruct it from the required threshold. Supports BIP39 seed phrases, keys, passwords, Base58/Hex/Base64 shares, QR codes, and offline recovery — entirely in your browser.
HKDF Key Derivation Tool
Derive cryptographic keys from a master secret using RFC 5869 HKDF (HMAC-based Key Derivation Function) in your browser. Supports SHA-256, SHA-384, SHA-512, configurable salt, info, and output length. Generate single or multiple derived keys instantly using the native Web Crypto API with zero server interaction.
Cryptographic Hash Generator
Generate SHA-256, SHA-512, SHA-384, and SHA-1 hashes for files and text locally in your browser. Verify checksums with zero uploads, Web Crypto API support, Web Worker processing, and chunked large-file reading.
Large File Checksum Verifier
Verify file integrity by comparing local files against published MD5, SHA-1, SHA-256, SHA-384, and SHA-512 checksums. Multi-GB support with Web Worker processing, zero uploads, and automatic algorithm detection.
Numeric Tolerance Matcher
Compare two lists of numbers with a margin of error, absolute or percentage tolerance, currency support, and financial reconciliation in your browser — all locally with no uploads.
Multi-List Venn Diagram Generator
Compare 3 lists online to find overlaps, intersections, and unique values. Interactive 3-circle Venn diagram with clickable regions, O(N) set operations, and full export — all in your browser with no uploads.
Browse Tools by Category
Discover browser-native utilities organized into categories for easier and faster tool discovery.
Developer Tools
Formatters, encoders, data tools, network utilities, markup tools, and API-adjacent utilities.
Text & List Tools
Text counters, converters, line tools, list comparison, list cleanup, and text generators.
Image & Design Tools
Image optimization, color tools, SVG tools, visual utilities, and social image helpers.
Calculators
Math, finance, date, unit, and numeric calculators.
SEO & Marketing Tools
Keyword tools, domain tools, email list tools, campaign utilities, and content marketing helpers.
Productivity & Time Tools
Timezone, scheduling, planning, office workflow, and productivity utilities.
Security & Privacy Tools
Encryption, password, key, hash, checksum, redaction, and metadata privacy tools.
Performance, Privacy & Simplicity
Built for Performance
Fast-loading utility tools optimized for speed, responsiveness, and minimal resource usage.
Privacy Focused
Most tools run directly in your browser, helping keep your data under your control.
Simple & Accessible
No accounts, no complicated setup, and no learning curve. Just open a tool and start working.
Your Privacy-First Utility Tool Library
FreeDeskTools.com comprises a library of free-to-use online tools for making your workflow smoother, quicker, and more private. With all utilities executed in your browser through client-side JavaScript, there's no need to transfer any personal data anywhere else. It's no uploads, registrations, or data logging involved whatsoever.
Be it a developer formatting JSON, a writer cleaning text, a designer compressing images, a marketer preparing keyword lists, or a student needing a calculator, FreeDeskTools.com offers useful tools to help anyone work privately and securely.
Every single tool available at FreeDeskTools.com will be provided absolutely free of charge with zero restrictions of any kind, ever. More privacy-friendly tools are always being added, inspired by user input.
Need a tool that isn't here yet?
We are constantly adding new utility calculators, formatters, and helper tools. Submit a suggestion and our team will build it. Free, open source, and privacy-friendly.