Tools tagged "developer"

Drop a ZIP / gzip (.gz) / tar / tar.gz (.tgz) file and inspect it inside the browser: file listing, text and image preview, per-file download, and re-pack everything as a single ZIP. macOS and Windows do not open .gz / .tar.gz natively — this tool fills that gap without installing any app. Nothing is uploaded to a server.

Drop a ZIP file to inspect its contents without extracting. See total entry count, archive size, compression ratio, archive comment, plus per-entry path, original / compressed size, compression method (Stored / Deflate / Deflate64 / BZIP2 / LZMA / Zstandard), last modified time, CRC32, encryption flag, and directory marker. Runs via a hand-rolled Central Directory parser — entry data is never decompressed and nothing is uploaded.

Convert plain text into figlet-style ASCII art banners (e.g. Hello → █▀▀█ ▀▀█ █░░ █░░ █▀▀█). Runs figlet (MIT) entirely in your browser with 10+ popular fonts (Standard / Big / Slant / Block / Ghost / Banner3-D …). Newlines and multi-line input are supported. The result is rendered in a monospaced view; copy it to clipboard or download as a .txt file. Common uses: section headers in source code, separator lines in CI logs, README titles, terminal MOTDs.

Drop **1D barcode images** (JAN-13 / EAN-13, JAN-8 / EAN-8, UPC-A, UPC-E, Code 128, Code 39, ITF / Interleaved 2 of 5, Codabar) and the tool extracts the encoded text and detected format. Useful for reading product JAN codes, package tracking labels, shipping inventory. Decoding is fully local via the Apache-2.0 licensed **@zxing/library**, with batch upload for multiple images at once. For QR codes use the separate `qr-decode` tool.

Free online 1D barcode generator. Create EAN-13 / EAN-8, UPC-A, Code 128, Code 39, ITF, Codabar (NW-7), MSI, JAN barcodes from numbers or text and export as PNG or SVG. Tune bar width, height, color, margin, and human-readable label. Check digits validated automatically. Everything is generated inside your browser — the value you enter never leaves your device.

Convert text to and from Base32 (RFC 4648 / TOTP 2FA secrets) and Base58 (Bitcoin addresses). Switch the variant (Base32 / Base58) and direction (encode / decode). UTF-8 byte based, so Japanese and emoji round-trip. Runs entirely in your browser.

Convert between plain text and Base64. Encode with an optional URL-safe variant; decoding accepts URL-safe (- _, no padding) automatically. UTF-8 safe and runs entirely in your browser.

Paste a bcrypt-format password hash (`$2a$10$N9qo8uLOickgx2ZMRZoMyeIjZAgcfl7p92ldGxad68LJZdL17lhWy` style) and see the four parts: algorithm version (`2a` / `2b` / `2y` / `2x`), cost (2^N Blowfish rounds), salt (22-char base64), and hash (31-char base64). The cost row shows the exponential workload (cost=10 → 2^10 = 1024 expanded rounds, cost=12 → 4×, cost=14 → 16×) and a rough wall-clock estimate on a 2026-era server (~100 ms at cost=10, ~400 ms at cost=12, ~1.6 s at cost=14) — useful when deciding whether to raise the cost on a legacy system. Each algorithm variant (`2a` from 1999, `2x` bug-compat, `2y` patched, `2b` recommended by OpenBSD) is explained in its own card. Nothing is uploaded. This tool only parses — it does not compute hashes, so it cannot recover the original password.

Convert between text and binary. Pick a mode (text → binary or binary → text). Text is encoded to UTF-8 bytes and each byte is shown as a zero-padded 8-bit binary number (emoji and non-Latin text convert correctly as multiple bytes). Toggle space separators via an option; on decode, spaces and newlines are ignored and the input is regrouped into 8-bit bytes. Everything runs in your browser — your input is never uploaded.

Turn a one-item-per-line list (numbers, words, haiku, office jargon, etc.) into N×N (3–7) bingo cards — generate up to 100 cards at once with a single seed for reproducibility. Supports a centre FREE cell (odd sizes only) and TSV export. Perfect for company events, classrooms, conferences, book clubs, and icebreakers.

Encode and decode the Caesar cipher. Pick a mode (encrypt / decrypt) and set the shift (1–25) with a slider or number field. One tap sets ROT13 (shift 13). Only A-Z / a-z are rotated; digits, punctuation, spaces, and non-Latin text are left intact. In decrypt mode, a full 25-shift brute-force table is shown to crack ciphertext with an unknown shift. Everything runs in your browser — your input is never uploaded.

Count characters, words, lines, paragraphs, and UTF-8 byte size in real time. Toggle whether whitespace and newlines are included. Progress bars show your text against common limits (tweets, 400-character genkō, etc.) — everything stays in your browser.

Convert Linux / macOS file permissions between octal (755 / 0755 / 4755) and symbolic form (rwxr-xr-x / rwsr-xr-t), or edit them directly with the owner / group / other checkboxes. Supports the setuid / setgid / sticky bits and accepts ls -l output with a leading file-type char (-, d, l, ...). Includes common presets such as 644 (regular file), 755 (directory or executable), 600 (SSH key), and 1777 (shared directory like /tmp). Runs entirely in your browser.

Interpolate between two colors (HEX or CSS names) to build an N-step palette. Two modes: RGB (straight RGB lerp) and HSL (hue traversal via shortest path). Great for Tailwind-style 11-shade scales, design-token shade generation, intermediate samples for `linear-gradient`, or stepped color ramps for accessibility. Click any swatch to copy its HEX; the full CSS `linear-gradient` string is also one click away. Everything runs in your browser.

Pick a foreground (text) and background color to compute the WCAG 2.x contrast ratio and instantly see whether it passes AA / AAA for normal text, large text, and UI components. Accepts HEX and rgb(), with a color picker and live preview. Everything runs in your browser — your colors never leave the page.

Convert colors between HEX, RGB, HSL, and HSV in real time with a built-in color picker. Edit any field and the other three update instantly. Runs entirely in your browser — your color values never leave the page.

Type a HEX value (`#3b82f6`) or a CSS color name (`tomato`) to find the closest matches across CSS named colors (148) and the Tailwind palette (22 hues × 11 shades). Results are sorted by RGB distance with a swatch, name, HEX, and distance score. Perfect for naming design tokens, communicating colors verbally, or finding the nearest Tailwind class. Everything runs in your browser.

Compute CRC-8, CRC-16 (CCITT-FALSE), CRC-16 (Modbus), CRC-32 (ISO-HDLC, ZIP/Ethernet) and CRC-32C (Castagnoli, SCTP/iSCSI) for the same input. CRC variants are the workhorse error-detecting checksums in binary protocols — ZIP/PNG/gzip frame trailers, Modbus industrial-control buses, SCTP/iSCSI, embedded firmware updates. They are not cryptographic hashes but they are tiny, fast, and fixed-width (8/16/32 bit). Input can be UTF-8 text or hex bytes; results are shown in both hex (uppercase) and decimal alongside each algorithm's polynomial, initial value, reflection flags and final XOR — useful for matching against datasheets. Everything runs in your browser; nothing is uploaded.

List the next 10–100 firing times for a cron expression like `0 9 * * 1-5`. Validate your crontab / GitHub Actions / Kubernetes CronJob / Vercel Cron Jobs schedules before deploying. Powered by cron-parser running entirely in your browser.

Paste a cron expression (`0 9 * * 1-5`, `*/5 * * * *`, `0 0 1 * *`, `@daily`, etc.) and get a plain-English (and Japanese) description in one click. Handles **POSIX 5-field crontabs** (minute / hour / day-of-month / month / day-of-week), **Spring / Quartz / GitLab 6-field** (second + 5), and **Quartz 7-field** (second + 5 + year). Recognises named day-of-week tokens (`MON` / `TUE` / `1-5`), named months (`JAN` / `FEB`), ranges (`1-5`), steps (`*/15`), and lists (`0,15,30,45`). A breakdown table shows what each field contributes. Pair with **cron-next** when you need the upcoming firing times instead of the description. Pure browser-side — no external calls. Own parser (~480 lines, zero dependencies).