Math & Numbers
Practice significant-figure rules with step-by-step feedback: count sig figs, round to N sig figs, convert to scientific notation, and propagate through +/−/×/÷.
significant-figures-sandboxDesign
A curated 2026 reference of image dimensions for Instagram, Facebook, X, LinkedIn, YouTube, TikTok, Pinterest and WeChat — filterable by platform.
social-media-image-size-cheatsheetText Processing
Generate clean URL slugs from any text, with built-in Chinese-to-Pinyin conversion. Collapse separators, lowercase, and optional max-length word-aware truncation.
slug-generatorDevelopment
Beautify or minify SQL with full control over dialect (PostgreSQL, MySQL, SQLite, SQL Server/T-SQL, BigQuery, Snowflake, and more), keyword / identifier / function casing, indent style (standard, tabular-left, tabular-right), and spacing between statements. Produces a syntax-highlighted, copy-ready result with live size and statement stats.
sql-query-formatterText Processing
Convert text to Unicode small capitals (ʜᴇʟʟᴏ). Uses Phonetic Extensions small-cap glyphs; letters without a dedicated glyph fall back to lowercase.
small-caps-converterText Processing
Add a strikethrough line through every character via the Unicode combining mark U+0336. Plain text — no markdown needed.
strikethrough-textMedia
Generate a stereo test tone file with independent left and right channel frequency, phase, waveform, and level controls.
stereo-signal-tone-generatorSecurity
Generate an SSH key pair (Ed25519 recommended, RSA 4096, or ECDSA P-256) with an OpenSSH-format public key ready for ~/.ssh/authorized_keys, a SHA256 fingerprint, and a PEM private key. Optional passphrase encryption. Runs locally.
ssh-key-generatorHealth
Calculate cumulative sleep debt across the last 7 to 14 nights and generate a gradual recovery plan
sleep-debt-calculatorDevelopment
Parse EXPLAIN / EXPLAIN ANALYZE output (PostgreSQL/MySQL/SQLite) into a cost tree, flag estimated-vs-actual row divergence, and suggest indexes
sql-explain-plan-visualizerMedia
Export one image into nine social-ready crops for Instagram, X, LinkedIn, YouTube, Facebook, Xiaohongshu, and TikTok
social-media-image-resizerMedia
Convert Sony SR2 RAW files to JPEG format. Automatically extracts image dimensions and metadata from the RAW file.
sr2-to-jpg