Browse the Codex
Every tool on The Magic Codex, organized into 16 categories. Pick one to see everything in it — all free, all in your browser, no sign-up.
Course Tools
Hands-on practice for The Magic Codex's free video courses. The Prompt Simulator scores your prompts 0–10 across 18 scenarios, from va…
Browse → 9 toolsFormula Sheets
Printable formula sheets for real college courses: Calculus I & II, Linear Algebra, Statistics, Physics I & II, General Chemistry I,…
Browse → 7 toolsLearn
Full course hubs that teach college material properly — not just formula lists. Each lesson covers one formula: where it comes from, t…
Browse → 35 toolsStudy Tools
Everything for homework, exams, and staying organized: GPA and grade calculators, citation generator, flashcards with spaced repetition, pom…
Browse → 7 toolsWriting & Text
Tools for writers and the curious: a Hemingway-style readability checker, an extractive text summarizer that runs in your browser, a cipher …
Browse → 12 toolsDev & Web
A toolbox for building the web: SQL formatter, WCAG color contrast checker, CSS gradient and box-shadow generators, flexbox/grid playground,…
Browse → 11 toolsCiphers & Codes
Secret codes, done properly: a historically faithful Enigma machine simulator (rotors, plugboard, ring settings), pigpen, rail fence, and Ba…
Browse → 7 toolsPuzzle Solvers
Stuck on a puzzle? Sudoku solver (backtracking, solves hard puzzles in under a second), Wordle helper with pattern filters, 24 game and coun…
Browse → 31 toolsCalculators
A calculator for everything: scientific, mortgage and payoff, rent-vs-buy, student loans, retirement and ROI, salary and take-home pay, infl…
Browse → 10 toolsHealth & Fitness
Know your numbers: calorie/TDEE, BMR, body fat (U.S. Navy method), macro splitter, ideal weight range, running pace, one-rep max, heart-rate…
Browse → 33 toolsMath
Serious math, in your browser: graphing calculator, matrix operations, systems of equations, numeric derivatives and integrals, triangle and…
Browse → 11 toolsScience
Lab and homework helpers for the sciences: chemical equation balancer (exact fractional math), molarity/dilution, molecular weight with a 11…
Browse → 3 toolsTime & Date
Small tools for time questions: time duration (hours and minutes between two times, overnight-safe), a day-of-week finder for any date, and …
Browse → 8 toolsEveryday & Fun
Life's little helpers: a habit tracker with streaks, a bill splitter that reconciles to the cent, a decision wheel, a savings goal tracker, …
Browse → 24 toolsText & Files
Work with text and files without uploading them anywhere: PDF tools (merge, compress, extract text, metadata, page numbers, text-to-PDF), ca…
Browse → 13 toolsUtilities
The junk drawer, organized: password generator, countdown timer, stopwatch, timezone converter, color picker, random number generator, base6…
Browse →More from the codex
About browsing
The codex grows every week — this index always lists every category.
- How is the site organized?
- Tools are grouped into 16 categories — study, math, finance, health, ciphers, and more — plus course tools, formula sheets, and full course hubs. Pick a category to see everything in it.
- Is everything really free?
- Yes. Every tool, simulator, formula sheet, and lesson on The Magic Codex is free with no sign-up.
- Where do I start?
- Students usually start with Study Tools or the Learn course hubs. If you're here for the video courses, head to Course Tools.
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