Free Online Tools for
AI, Developers & Students
Format, encode, calculate, and transform your data instantly. Files and text you enter are processed in your browser with sourced formulas and transparent pricing data.
Featured Tools
Our most frequently used utilities across AI, academic writing, and developer workflows.
A/B Testing Statistical Significance Calculator
Calculate conversion rate uplift, two-tailed Z-scores, and statistical significance confidence for A/B split tests.
AI Prompt Formatter & XML Tag Builder
Format high-performance system prompts using Anthropic-recommended XML tags and structured Markdown delimiters for frontier LLMs.
Assignment Deadline & Schedule Planner
Break essays, research papers, and homework assignments into structured daily study milestones and writing targets.
Final Grade Calculator
Calculate the exact exam score required to pass your course or earn your target letter grade.
Words to Pages Calculator
Convert word counts to exact document pages based on line spacing, font family, and font size for essays and research papers.
Citation & Bibliography Generator
Generate instant, clean APA 7th, MLA 9th, Chicago, and Harvard references and in-text citations for websites, books, and journals.
CIDR & IPv4 Subnet Mask Calculator
Compute network address, broadcast address, usable IP host ranges, binary notation, and wildcard mask from any IPv4 address and CIDR prefix.
SaaS Unit Economics & CAC / LTV Calculator
Calculate Customer Lifetime Value (LTV), Customer Acquisition Cost (CAC), Payback Period, and Rule of 40 score for SaaS businesses.
Trending Now
Schema.org JSON-LD Structured Data Generator
Generate Google Rich Snippet-compatible JSON-LD structured data markup for Articles, FAQs, Software, Products, and Organizations.
AI Embedding Cost & Vector Memory Calculator
Calculate vector embedding generation costs, dimensions, and HNSW Vector DB RAM requirements for RAG architectures.
cURL to Code Converter
Convert raw cURL commands into JavaScript Fetch, Axios, Python Requests, and Go HTTP client code.
Social Media Character Limit Tester
Test copy length in real-time against character and word limits for Twitter/X, LinkedIn, Instagram, Google Ads, and SMS.
Word Frequency Counter & Keyword Density Tool
Analyze word recurrence, unique vocabulary, and keyword density percentages with stop-word filtering.
Color Palette Generator
Generate complementary, analogous, triadic, and monochromatic color palettes with instant CSS export.
UTM Campaign Tracking Link Builder
Generate standardized Google Analytics 4 (GA4) UTM tracking URLs for ads, newsletters, and social media campaigns.
Google SERP Snippet Simulator
Preview how your web page appears on Google Desktop and Mobile search results with pixel width calculations.
Recently Added
PDF Splitter & Page Extractor
Split PDF files and extract custom page ranges locally in your browser with zero server uploads.
AI Background Remover
Remove the background from any image instantly using in-browser Artificial Intelligence. 100% private and free.
Free PDF Invoice Generator
Create, preview, and download professional PDF invoices for your freelance business completely free.
Essay Word Counter & Analyzer
Count words, characters, and paragraphs for your academic essays. Instantly estimates reading level and speaking time.
College GPA Calculator
Calculate your cumulative and semester GPA on standard 4.0 unweighted and 5.0 weighted Honors/AP scales.
Freelance Hourly Rate Calculator
Calculate your required freelance hourly rate based on target annual salary, business overhead expenses, vacation weeks, and billable utilization percentage.
Crypto Profit & Tax Calculator
Instantly calculate your net profit and capital gains tax from cryptocurrency trades.
Cloud Infrastructure Cost Estimator
Estimate and compare monthly cloud infrastructure costs across AWS (EC2), Azure, and GCP including compute instances, block storage, and data egress.
Explore All 9 Category Hubs
Find purpose-built utilities organized across AI, software engineering, student writing, and business math.
AI Engineering
Token counters, context window comparisons, vector embedding memory calculators & API budgets.
Student & Academic
Weighted GPA, final grade targets, words to pages, APA/MLA citations & assignment deadline planners.
Developer Tools
cURL to code, JSON to TypeScript, Cron expression builder, CIDR subnets, JWT & JSON-LD.
Business & SaaS
SaaS LTV/CAC unit economics, A/B testing statistical significance, ROI & profit margin calculators.
Calculators
PayPal & Stripe fees, cloud costs, mortgage loans, EMI, percentages, BMI, and age.
Text & Writing
Word frequency analyzer, character limit tester, diff compare, slug generator & case converter.
Image Tools
Image compressor, resizer, cropper, format converters (PNG/JPG/WebP/SVG), EXIF & background remover.
Converters
CSV to JSON, XML to JSON, Markdown to HTML, Unix timestamps, and unit conversions.
PDF Utilities
Split PDF page ranges and merge documents directly in your browser using pdf-lib.
Built for accuracy, speed & transparency
Many online calculators hide their formulas, rely on outdated pricing tables, or require account signups before showing results. Heptiq is built around verifiable math and browser-based execution.
Processed in Your Browser
Files and text you enter are processed in your browser using JavaScript and WebAssembly.
Sourced Formulas & Dated Rates
AI model prices and payment processor fees include official source links and verification dates.
Lightweight, non-intrusive ads
Supported by non-intrusive display ads in reserved layout slots so every tool remains free without paywalls.
// Parsed in browser memory
try {
return JSON.stringify(JSON.parse(input), null, 2);
} catch (e) {
return e.message;
}
}
107
Interactive Web Utilities
9
Specialized Topic Hubs
45
Technical Reference Guides
Frequently Asked Questions
Everything you need to know about the platform.
Are the tools completely free to use?
How are my files and text handled?
How is Heptiq funded?
How often are pricing rates and formulas verified?
Latest Guides
Learn how to maximize your workflow with our in-depth tutorials.
How to Properly Format JSON Payloads for REST APIs
Learn the standard practices for organizing and nesting JSON structures for optimal API transmission and parsing performance.
Understanding Base64 Encoding: A Complete Guide
A deep dive into how binary data is translated into 64 ASCII characters for safe web transport and storage.
The Math Behind Loan Amortization & EMIs
Unpacking the complex formulas that power Equated Monthly Installments and how interest compounds over time.