Free tools for builders & businesses
Format JSON in seconds, calculate your SaaS ad ROI, and more. No sign-up. Our tools run 100% in your browser; ads are served by our partner Monetag.
💼 B2B & Finance Tools
SaaS ROI Calculator
Know your ROAS, CAC and break-even before spending a dollar on ads. Built for SaaS & B2B marketers.
🎧 Audio Tools
Audio Converter
Convert MP3/OGG to WAV — then trim, fade, reverse, normalize. A mini audio editor in your browser.
⭐ Recommended gear
YubiKey 5 NFC
Phishing-proof hardware security key. Tap to log in to 100+ services — the perfect companion to strong passwords.
Check price on AmazonFIFINE K669B Microphone
USB condenser mic, plug & play. Clean audio in means clean WAV out — ideal for voice and podcasting.
Check price on AmazonAs an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
📝 From the blog
How to Validate and Format JSON in Seconds
SaaS ROI: Know Your ROAS Before Spending on Ads
How to Compress Images Without Losing Quality
10 Free Online Tools Every Developer Should Bookmark
JPEG vs PNG vs WebP vs SVG: Which Format Should You Use?
Audio Bitrate Explained: 64 vs 128 vs 320 kbps
🧰 Web & Developer Utilities
JSON Formatter & Validator
Paste messy JSON, get clean formatted output. Validates syntax and shows exactly where errors are.
Image Compressor
Convert between JPG, PNG, WebP — even SVG to PNG. Shrink, resize, right in your browser. Private and free.
Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to readable text. Instant, private, free.
Password Generator
Create strong, random passwords with custom length and character sets. Entropy meter included.
JSON Formatter & Validator
Paste your JSON below. Format it, minify it, validate it, or convert it to XML, CSV, YAML — all locally, nothing leaves your device.
Audio Bitrate Explained · JPEG vs PNG vs WebP vs SVG · 10 Free Tools for Developers
SaaS ROI Calculator
Enter your campaign numbers and instantly see ROAS, CAC, ROI and how many customers you need to break even.
Formula: ROI = (Gross profit − Ad spend) ÷ Ad spend. ROAS = Revenue ÷ Ad spend. Break-even customers = Ad spend ÷ (ARPC × margin).
Audio Bitrate Explained · JPEG vs PNG vs WebP vs SVG · 10 Free Tools for Developers
Image Converter & Compressor
Reduce image file size without visible quality loss. 100% private — your images never leave your browser.
or click to browse — JPG, PNG, WebP, GIF, BMP, SVG
Audio Bitrate Explained · JPEG vs PNG vs WebP vs SVG · 10 Free Tools for Developers
Base64 Encoder & Decoder
Convert text to Base64 and back. Everything runs locally — nothing is sent anywhere.
Audio Bitrate Explained · JPEG vs PNG vs WebP vs SVG · 10 Free Tools for Developers
Password Generator
Strong, random passwords generated locally in your browser. We never see or store them.
A strong password is step one. A YubiKey 5 NFC hardware security key adds phishing-proof two-factor login to 100+ services — tap to authenticate, no codes to type.
Audio Bitrate Explained · JPEG vs PNG vs WebP vs SVG · 10 Free Tools for Developers
Audio Converter
Convert MP3, OGG or WAV to WAV (PCM) — then trim, fade, reverse, normalize or resample. A mini audio editor that runs 100% locally; nothing is uploaded.
or click to browse — MP3, OGG, WAV
✂️ Trim cut silence or unwanted parts
🎛️ Effects fade, reverse, normalize, channels, sample rate
🏷️ Track info title, artist, album… saved in the WAV
Note: WAV is uncompressed, so the output file is larger than the MP3. That's normal — it's the price of lossless quality for editing.
Converting audio to WAV? Start with clean audio: the FIFINE K669B USB condenser microphone is plug & play — ideal for voice, podcasting, and online classes.
Audio Bitrate Explained · JPEG vs PNG vs WebP vs SVG · 10 Free Tools for Developers