Online Tools

Browse 137 free PocketKit tools for development, images, PDFs, conversion, text, calculations and going-global work. Networked features are clearly identified.

📌 TL;DR Directory Summary: The directory contains 120+ utilities. Core file processing avoids uploads; live-data tools disclose their network destination, and aggregate usage counts exclude tool input.

Developer Tools

AI Prompt & System Prompt Generator — Structure and optimize system prompts for DeepSeek, Claude, and ChatGPT with code review, translation and content templates
Claude Env Scanner & Region Checker — Check browser timezone, system locale, language, and font fingerprints to detect Claude region blocking or account ban risks, helping you secure proxy configurations.
Claude Proxy Network Checker (Exit IP & Timezone) — Detect your real exit IP and region, cross-check it against system timezone, language and WebRTC leaks to find proxy exposure points and reduce Claude ban risk
AI Token Counter & Cost Estimator — Estimate token counts locally and compare API costs across Claude, GPT, Gemini and DeepSeek models
LLM API Pricing Comparison — Compare input/output/cached prices, context windows and blended cost across Claude, GPT, Gemini and DeepSeek
Tool & Function Schema Converter — Convert between Claude tool, OpenAI function, Gemini functionDeclaration and JSON Schema — with strict mode
Multimodal Vision Token Counter — Calculate image tile vision tokens and API cost for GPT-4o, Claude 3.5 Sonnet and Gemini 1.5
System Prompt Anti-Leak & Jailbreak Auditor — Audit system prompt robustness against 20+ LLM injection patterns and auto-patch structural directives
JWT Parser — Decode and parse JWT tokens offline
Cron Generator — Generate and parse Cron expressions with execution schedule preview
Keycode Info — Get keyboard event key, code, and keycode details
User Agent Parser — Parse User Agent strings to identify browser, OS, and device
Bcrypt Generator — Generate and verify Bcrypt password hashes
HMAC Generator — Compute HMAC signatures (SHA256/512) for messages
IPv4 Subnet Calculator — Compute subnet mask, network range, usable IPs and binary format
Docker Compose Converter — Convert docker run commands to docker-compose.yml format
Chmod Calculator — Calculate Linux file/directory permission values and command
BIP39 Generator — Generate and verify multi-language BIP39 mnemonic phrases
ULID Generator — Generate lexicographically sortable unique identifiers
URL Parser — Parse URL structures and edit query parameters interactively
JSON Formatter — Format, minify and validate JSON
Timestamp Converter — Convert between Unix time and dates
URL Encode/Decode — Encode / decode URL components
Base Converter — Convert between 2/8/10/16
ASCII Table — Look up ASCII 0-127
HTTP Status Codes — Common status codes reference
Password Generator — Generate secure random passwords
Docker Command — Build a docker run command
Windows Commands — Generate common Windows commands
Linux Commands — Generate common Linux commands
Regex Tester — Test regex matches and groups live
UUID Generator — Generate UUID v4 in bulk
Hash — MD5 / SHA-1 / SHA-256…
AES Encrypt — AES-256-GCM with password
RSA — Generate keypair, encrypt/decrypt
MIME Types — Extension ⇄ MIME lookup
Code Formatter — Beautify JS / JSON / CSS / HTML
UCharts Builder — Create beautiful interactive charts from raw data grids locally
SQL Formatter — Beautify SQL by breaking and indenting at major clauses and normalizing keyword case
JSON to Types — Infer TypeScript interfaces, Go structs or Python TypedDict from JSON, with nested types and array merging
GPT Token Counter — Count GPT-4o/4/3.5 tokens exactly with OpenAI's official BPE (o200k/cl100k) locally and estimate cost
cURL to Code — Convert a curl command into JS fetch / axios / Python requests / Go code, detecting method, headers and JSON body

Going-Global Tools

Privacy Policy Generator — Generate an English privacy policy for App Store / Google Play / Stripe with GDPR / CCPA clauses
Test Card Numbers & Luhn Check — Validate card numbers (Luhn) and brand, generate valid test numbers, and list common gateway test cards
Stripe Fee & Net Calculator — Compute Stripe fees and net payout, reverse-solve the charge for a target net, plus international / FX surcharges
Multi-Currency & Charm Pricing — Convert one base price to many currencies with .99 / round charm pricing for global pricing pages; editable rates, offline
VAT / GST Calculator — Look up VAT/GST standard rates by country and convert net ⇄ gross for cross-border invoicing
Stripe vs Lemon Squeezy vs Paddle Comparison — Compare net payout, MoR global tax filing and processing fees between Stripe, Lemon Squeezy and Paddle
Purchasing Power Parity (PPP) Pricing Calculator — Calculate localized PPP discount pricing for 40+ countries based on World Bank indices and export JSON
DNS Lookup — Query A / AAAA / MX / TXT / NS / CNAME / CAA records via Cloudflare DNS-over-HTTPS, right in your browser
Email Deliverability Check (SPF/DKIM/DMARC) — Check a domain's SPF, DKIM and DMARC records with fix-it advice to improve inbox placement for outbound mail
Deploy Config Generator — Generate _headers / _redirects (Cloudflare Pages / Netlify) and vercel.json — SPA fallback, security headers, caching, redirects
CORS Config Generator — Configure CORS headers visually and generate Express / Nginx / Cloudflare Worker snippets, with credentials/wildcard warnings
robots.txt Generator — Build robots.txt from per-user-agent groups with Allow/Disallow, Crawl-delay, Sitemap and one-click AI-crawler blocking
i18n JSON Checker — Diff two locale JSON files for missing/extra keys and placeholder mismatches — essential for frontend i18n
hreflang Tag Generator — Generate hreflang and x-default tags for multilingual sites (subdir / subdomain / query strategies) to avoid duplicate content
Timezone Meeting Planner — From your local time, see the same moment across US/EU/Asia zones with day-offset — for scheduling meetings and launches
UTM Link Builder — Build UTM-tagged tracking URLs with consistent source/medium/campaign naming for ads, email and social attribution
Open Graph Meta Generator — Generate Open Graph and Twitter Card meta tags with a live social-card preview for rich link previews on Facebook, X and chat apps

Download Tools

TikTok Video Downloader — Parse public TikTok links and save available MP4 video or extract its audio. Resolution and watermark status depend on the source media stream.
TikTok MP3 Sound Downloader — Extract complete audio tracks and BGMs from public TikTok videos, preview them online and save MP3 when available. Bitrate depends on the source audio.
Suno AI Music Downloader — Parse public Suno AI music links and retrieve available audio, artwork and lyrics. Formats and quality depend on the public source item.
Suno AI Video Downloader — Parse public Suno links and save available MP4 music videos. Resolution, captions and availability depend on the source item.

Calculators

Loan Calculator — Monthly payment, total interest and full amortization
Percentage Calculator — X% of Y, ratios and percent change
Discount Calculator — Sale price and savings, with stacked discounts and tax
Tip Calculator — Tip and total by rate, split across people
Sales Tax Calculator — US state sales tax, with tax-inclusive reverse mode
Compound Interest Calculator — Compound growth with optional monthly contributions
GPA Calculator — Calculate overall and semester GPA with course grades, credits and various grading scales (4.0, 4.3, 5.0, WES).
BMR & TDEE Calculator — Compute Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) with Mifflin-St Jeor & Harris-Benedict formulas.
Mortgage Refinance Calculator — Compare your current mortgage with refinance options to find monthly savings, total interest saved, and the break-even period.
Currency Converter — Convert 30+ currencies at live mid-market rates with edge caching and offline fallback — for global pricing and expenses

PDF Tools

Merge PDF — Combine multiple PDFs
Split PDF — Split PDF by page or range
Organize PDF — Delete / rotate / reorder pages
PDF to Image — Export each page as PNG
PDF Password — Add or remove PDF password

Converters

Base64 Encode/Decode — Convert text to/from Base64
Unit Converter — Convert length, weight, temperature…
ZIP Extractor — Unzip locally and download files
Byte Calculator — Convert B / KB / MB / GB
Punycode — IDN domain ⇄ Punycode
Data Converter — Convert CSV / JSON / XML

Image Tools

AI Image Ratio & Resolution Calculator — Calculate exact pixel resolution, aspect ratios and --ar parameters for Midjourney, Flux.1, and SDXL image generators
Photo Exif & GPS Privacy Cleaner — 100% in-browser removal of photo GPS locations, device models, exposure and Exif privacy metadata
QR Code Generator — Turn text or links into a QR code
WiFi QR Code — Generate a QR code to connect to your WiFi network
SVG Placeholder — Generate and download custom SVG placeholder images
Color Converter — Convert between HEX / RGB / HSL
Image Compressor — Compress images locally
Image Converter — Convert PNG / JPG / WebP
AI Background Remover — One-click AI cutout in your browser — no upload
ID Photo Maker — Auto cutout, bg swap & standard ID sizes
Screenshot Beautifier — Add gradient background, rounded corners & shadow
Signature Pad — Draw a signature, export PNG
Screen Color Picker — Sample any color on screen
Grid Splitter — Split an image into tiles, zip them
Images to PDF — Combine images into one PDF
Image to Base64 — Image to DataURL / CSS
Favicon Maker — Export PNG icons of each size
Image Crop — Drag to crop an image
Image Effects — Grayscale / flip / border / pixelate
EXIF Viewer — View & strip image metadata
Image to Pixel Art — Convert images locally into retro 8-bit pixel art styles
Art Avatar Generator — Customize and generate beautiful vector avatars with SVG/PNG exports
CSS Gradient Generator — Visually tune angle and color stops to preview and generate linear/radial gradient CSS
CSS Box-Shadow Generator — Visually build multi-layer box-shadow and inset shadows with live preview and copyable CSS
Glassmorphism Generator — Generate frosted-glass (glassmorphism) effects with backdrop-filter — tune blur/opacity/border and copy CSS
Contrast Checker (WCAG) — Check foreground/background contrast against WCAG accessibility levels (AA/AAA) with a live readability preview

Text Tools

Word Counter — Count characters, words, lines
HTML ⇄ Markdown — Convert between HTML and Markdown
Case Converter — Convert strings between camelCase, snake_case, kebab-case etc.
List Converter — Convert simple lists into JSON arrays, SQL IN lists, or CSVs
HTML Entities — Encode and decode HTML entity character representations safely
Stealth Reader — Blog-disguised TXT novel reader
Text Diff — Highlight line-by-line differences
Special Symbols — Symbol library, click to copy
Emoji Picker — Emoji by category, click to copy
ASCII Art — Turn text into ASCII banners
Chinese Convert — Simplified ⇄ Traditional Chinese
Markdown Table Generator — Edit tables visually and generate Markdown table code, with per-column alignment, add/remove rows and columns
Lorem Ipsum Generator — Generate classic Lorem Ipsum placeholder text by paragraphs, sentences or words for layout mockups
Text Line Tools — Dedupe, sort, drop blanks, trim and reverse text by line — batch-clean text with live toggles

Audio & Video

Text to Speech — Read text aloud
Online Piano — Play with keyboard or mouse

Lifestyle Tools

BMI Calculator — Calculate body mass index
Stopwatch — Timing with laps
Day Counter — Days to / since a date
ID Card Check — Validate & parse ID numbers

Fun & Games

Reaction Test — Test your reaction time
What to Eat — Decide what to eat
Filler Text — Topic → long filler text
Payment Voice — Speak a payment-received line
Shape Recall Game — Recreate random geometric shapes from memory by dragging, scaling, and rotating
Time Memory Game — Test your time perception by holding down a button to match system pulse durations
Sound Memory Game — Test your pitch memory by matching sound wave frequencies with a tone slider

Frequently Asked Questions (FAQ)

Which tools avoid file uploads?

Most PDF, image, text and cryptographic tools process core input in the browser. Live data, network checks and download parsing require network access; check tool-page labels and the data-processing directory for exact behavior.

How do I find a specific utility quickly in the directory?

Use the category filter buttons (Dev, Oversea, PDF, Calculators, etc.) to filter the directory instantly, or type keywords in the search bar for live search results.

Will these tools work if my internet connection drops?

Some text, calculation and file tools may continue after required resources are cached, but offline availability depends on browser cache, dependencies and the device. Rates, DNS and download parsing do not work offline.

Technical Specifications & Standards

Different tools reference the public specifications relevant to their task. These are foundational references for PDF, JWT and browser file handling; check each tool page for its implementation scope and limits:

ISO 32000-2 (PDF 2.0): Document management — Portable document format standard.
IETF RFC 7519 (JWT): JSON Web Token (JWT) layout and signature guidelines.
W3C File API: Standard client-side file reading and buffer processing interfaces.