Tab Previews
┊ Live Preview
Select Preprocessor
Create Read.Me
Create a local read-only copy of your current tab:
Share Tab
The shared tab will open in the same editor interface with view-only access.
Users can view expired Read.me tabs in fullscreen mode.
Editors are read-only in shared view.
Choose Preview Device
Select the device type for your fullscreen preview
🔍 Code Analyzer
Ready to analyze
Select a tab and click Analyze to scan your code for issues with AI
Create Backup
Important Notice
Before you create a backup:
- Backups are stored in your browser's LocalStorage only
- They will be lost if you clear browser data
- They will be lost if you restart your browser
- Backups are not synced across devices
- They are stored locally on this device only
Do you understand and want to continue?
Backup Created
Backup created successfully!
Access this backup anytime from the Backups list.
Choose a Category
No templates match your search
This will open the template in a new tab in the editor. Your existing tabs will not be changed.
Backup Manager
No backups found
Click "Create Backup" to save your work
Third-Party Service Notice
The Insert Media feature uploads files directly from your browser to a free third-party hosting service. We have no affiliation with these services.
Choose a Service
Select which service to upload to. Click a card to select it — details will appear below.
Any file · Max 1 GB
Insert Media
Drop a file here or browse
Click Insert to place the URL at your cursor, or copy it manually.
Media Library
No media saved yet.
Uploaded files will appear here.
Upload History
No uploads yet this session.
Storage Usage
Storage Almost Full
Your browser's localStorage is almost full.
What uses storage:
- Saved tabs (code content)
- Backups
- Media library (URLs only)
- AI cooldown timer
To free space:
- Delete old backups you no longer need
- Close saved tabs you're done with
- Clear media library
Back up your code
Browser storage can vanish — clear cache, different device, server reset. Download a ZIP now so your work is safe no matter what.
Understand the risks
- 🗑️Clearing browser data or cache permanently deletes all saved tabs
- 📱Saved tabs are device & browser specific — not synced anywhere
- 🌐If the site goes down, your data goes with it unless you exported
- ⚠️We provide no data retention guarantee during beta
Save to browser
Your tab will be saved in this browser's LocalStorage and reload automatically next visit.
Success
Tab saved successfully!
This tab will now appear every time you visit this site.
Saved tabs are marked with a 💾 icon.
Delete Saved Tab
⚠️ Permanently Delete Saved Tab?
This saved tab will be permanently deleted from localStorage.
This means:
- 🗑️ The tab will be completely removed from storage
- 💾 It will NOT reappear when you reload the page
- 🔄 This action cannot be undone
Are you sure you want to permanently delete this saved tab?
Welcome to ptero.us.ci, ptero is an online html editor — all running directly inside your browser.
- Live HTML, CSS & JS editor with instant preview
- Mobile device simulator (100+ device presets)
- Multi-tab workspace with fork & save
- AI-powered code fixer (fixes lines automatically)
- Code Analyzer with HTML, CSS & JS breakdown
- Browser-based backup system
- Real-time collaboration via WebSocket
- Code sharing with expiry links
- Monaco Editor (same engine as VS Code)
- Preprocessor support: SCSS, Less, TypeScript, Babel, CoffeeScript, Pug, Markdown
The AI button lets you automatically fix specific lines of code using the AI service.
- Click the AI button in the editor toolbar
- Enter the line number you want fixed
- Click Fix Line — the AI will rewrite that line
- Lines are counted HTML first, then CSS, then JS
Backups save your current tab content to your browser LocalStorage. They are fast and private, but have important limitations.
- Backups are stored only in this browser on this device
- Clearing browser data deletes all backups permanently
- Backups do not sync across devices or browsers
- They are not saved to the server
- Click Backups in the editor bar, then Create Backup
- To restore, open Backups and click Load Backups
- Each backup is identified by a unique timestamp ID
- You can delete individual backups or select all and delete in bulk
Tabs let you work on multiple separate projects in the same editor session.
- Add Tab — creates a new empty workspace
- Fork Tab — duplicates the current tab with a new name
- Save Tab — saves the tab to LocalStorage so it reappears on reload
- Duplicate Tab — creates an identical copy
- Close All Tabs — removes all unsaved tabs
Saved tabs are marked with a 💾 icon and will automatically reload when you visit the page. Deleting a saved tab removes it permanently from LocalStorage.
Share your code with a temporary link that expires automatically.
- Click Share and choose an expiry time (1–10 minutes)
- A unique short URL is generated and copied to your clipboard
- Anyone with the link can view the shared tab in the editor
- The link expires automatically at the chosen time — expired shares show a 404 page
- Share data is encrypted in the redirect URL using AES-256-GCM so it cannot be tampered with in transit
- Maximum share payload: 128 KB per tab (HTML + CSS + JS combined)
- The server keeps up to 100,000 active share records before the oldest are pruned
Do not share code containing passwords, API keys, or confidential information.
You are on the Free Plan. Here is a full breakdown of what is included and what applies — updated for v5.9.0.
- Unlimited tabs (session only or saved locally)
- All device presets (100+ devices)
- All preprocessors (SCSS, Babel, TypeScript, etc.)
- Browser-based backups (LocalStorage)
- Code collaboration (join as guest or host)
- AI line fixer (with 60s cooldown, 10,000 req/day global pool)
- Code Analyzer with two-layer response cache
- Fullscreen editor mode
- 60-second AI cooldown between each AI request per IP
- 10,000 AI requests / day shared across all users globally
- Public code sharing is admin-only
- Backups stored in browser only (no server sync)
- Share payload limit: 128 KB per tab