PARSE runs your code in 15 languages in a secure sandbox and teaches it with AI — in plain English and technical depth. Six modes, one workbench, plus a deep AI toolkit.
🚀 Quick start (30 seconds)
- Pick a language from the dropdown (each loads a ready-to-run starter).
- Write or edit code in the editor.
- Hit ▶ Run — it executes in the sandbox and shows output + exit code + timing.
- Hit 🧠 Explain for a line-by-line breakdown, or 🔬 Analyze for complexity/review/security/optimize/diagram. 🗑 Clear resets.
New AI toolkit: 🔬 Analyze (Big-O · Review · Security · Idioms · Optimize · 🗺️ Diagram · 🌉 Bridge) · 🔧 Fix-it & Explain-error on failures · 🎓 Learn mode (mastery tracking · flashcards · challenges) · streaming answers · 🧠 Socratic mode · 🎤 voice · 🔊 read-aloud · 📚 benchmarks · 📥 GitHub load · 🔗 Share.
✍️ Write — run & understand
- Choose a language, type code, ▶ Run to execute it live.
- 🧠 Explain gives a dual-mode breakdown. Toggle 🧑 Plain (everyday analogies), 🔬 Technical (precise CS), or 📚 Both (default) in the output header.
- Errors show the exact file, line, and a
^ caret — break something on purpose to learn where & why.
🔀 Compare — race languages side-by-side
- Write your code in one language in the editor.
- Tick the languages you want to race against in the "Race against" bar.
- Hit 🔀 Compare — PARSE AI-translates your code into each one, runs them all, and shows a speed scoreboard (🏆 marks the fastest; the color bars show relative time).
🔎 Explain My Code — bring your own code
- Switch to Explain My Code.
- Paste any code into the editor, or click 📁 Upload to load a file.
- Hit 🔎 Detect & Explain — PARSE auto-detects the language and explains it line-by-line (dual-mode toggle applies).
🛠️ Build It — AI writes the code
- Switch to Build It, pick your language.
- Describe what you want in plain English (e.g. "a function that checks if a number is prime, tested on 1–20").
- Hit 🛠️ Build — an AI coding agent writes a complete program into the editor. Then ▶ Run or 🧠 Explain it.
💬 Ask PARSE — ask anything
- Switch to Ask PARSE.
- Type a concept question — "what is a string?", "why the parentheses here?", "what does this line do?" — and press Enter.
- It answers in plain English first, then technical depth, using the code in your editor for context (so "here" and "this" work). Answers stream in live; flip on 🧠 Socratic to be guided with questions instead.
🔬 Analyze — deeper looks at your code (Write mode)
Click 🔬 Analyze to reveal one-click lenses:
- ⏱️ Complexity Big-O time & space · 📋 Review graded quality · 🛡️ Security risky-pattern scan · ✨ Idioms style coaching · 🚀 Optimize faster rewrite (Apply to editor) · 🗺️ Diagram logic flowchart · 🌉 Bridge from… explain as if you know another language.
- When your code errors, 🔧 Fix it for me repairs & re-runs it, and 🧠 Explain this error gives the plain cause + fix.
🎓 Learn — a tutor that remembers you
- 📊 Mastery — Explain / Build / complete challenges and PARSE tracks concept mastery (Bayesian Knowledge Tracing) as bars. Stored privately in your browser — no account.
- 🃏 Flashcards — make spaced-repetition cards from your editor and tap to flip.
- 🎯 Challenges — get a task, solve it in the editor, and ✅ Check my solution runs & grades it.
🧰 Handy extras
- 📚 Benchmark task (Compare) loads a classic program to race · 🧠 Why these results? explains the winner.
- 🤔 Which language? (Build) recommends a language · Build self-corrects if the code errors.
- 📥 GitHub (Explain) loads a raw/gist URL · 🔊 reads aloud · 🎤 dictates · 🔗 Share copies a link that restores your code + mode.
🔗 Link an AI agent (Claude or any other) to PARSE
The Co-pilot Link lets anyone — you or a classmate — drive PARSE with their own AI agent, in a genuine two-way back-and-forth. Nothing to install, no account.
- Click the 🔗 Link button (top-right). It turns on and shows a 6-character code (e.g.
k4n2mx).
- Give that code to your AI agent — e.g. tell Claude Code: "Connect to PARSE at https://parseapp.dev with code k4n2mx and build me a bubble sort in Python."
- Your agent sends an instruction → PARSE's own AI does the work (answers, or writes & runs code) → it sends the result back → your agent reacts and sends the next step. A real conversation, live in your browser.
- Click 🔗 Link again to turn it off. Keep the tab open while linked — it executes each task and replies.
For developers / any AI agent — the relay is 2 HTTP calls (base =
https://parseapp.dev). Use the 6-char code shown by the Link button:
POST https://parseapp.dev/api/link/push {"code":"k4n2mx","text":"build a prime checker and run it"}
-> {"task_id":"abc123..."}
GET https://parseapp.dev/api/link/result?task_id=abc123 (poll until status=="done")
-> {"status":"done","reply":"Built + ran in Python ...\n--- output ---\n..."}
A question (ends with "?" or starts with what/why/how/is/…) is answered by the tutor; anything else is a build request — PARSE writes the code, runs it, and returns the code + output. Codes expire after 30 minutes.
💡 Tips
- Everything runs in a network-isolated sandbox — code you run can't reach the internet or your network. Safe to experiment.
- Compiled languages (C++, Rust, Go, Java, COBOL) genuinely compile then run — their timing is higher than interpreted ones.
- Switch modes anytime from the top tabs; your code stays in the editor.