Base64 encode và decode online miễn phí

Base64 encode và decode online

Search for “base64 encode”, “base64 decode” or “base 64 encoding” and you need a fast, accurate converter—not a signup wall. This page is a free Base64 encode and decode tool that runs in your browser: left box encodes, right box decodes, with live mode, UTF-8 and every common Base64 dialect.

Cần trang riêng? Base64 encode online · Base64 decode online · String to Base64 · Ảnh sang Base64 · MP3 to Base64 · Base64 to WAV · URL sang Base64.

Cũng phổ biến từ tìm kiếm: Kiểm tra nén gzip · WhatsApp link generator · LinkedIn hashtag generator · Hashtag generator for Twitter · Hashtag generator Facebook · IBAN checker · Bytes converter · Color contrast checker.

Tại sao nên dùng công cụ chuyển đổi Base64 này?

• Riêng tư ngay từ thiết kế. Văn bản và tệp của bạn được xử lý cục bộ bằng JavaScript. Ngay cả tệp lớn hay tệp bảo mật cũng không bao giờ rời khỏi thiết bị của bạn.
• Xử lý Base64 thực tế. Data URI, ngắt dòng, ký tự an toàn cho URL và thiếu padding đều được chấp nhận tự động, còn lỗi được chỉ ra đúng ký tự gây lỗi.
• Mọi chuẩn. RFC 4648 chuẩn, Base64URL, MIME, PEM, IMAP, XML và OpenPGP armor.
• Mọi bộ ký tự. UTF-8, UTF-16, Windows-125x, ISO-8859-x, Shift_JIS, GBK, Big5, EUC-KR, KOI8 và nhiều hơn nữa.
• Kết quả dán dùng ngay. Nhận data URI, quy tắc CSS, thẻ HTML, đoạn JSON hoặc XML thay vì một chuỗi trần.

Base64 hoạt động thế nào trong 30 giây

Base64 lấy mỗi lần ba byte (24 bit), chia thành bốn nhóm 6 bit và ánh xạ mỗi nhóm sang một trong 64 ký tự. Ví dụ, từ Man (các byte 77 97 110) trở thành TWFu. Đọc thuật toán từng bước hoặc bắt đầu với Base64 là gì?

Common uses include MIME e-mail attachments, data URIs in HTML and CSS, binary fields in JSON or XML, HTTP Basic authentication, and PEM-encoded certificates. When you need the reverse path, use Base64 decode online; to produce Base64 from scratch, use Base64 encode online.

Advanced options

• Character set. Base64 encodes bytes. Choose UTF-8 (default) or a legacy charset before encoding, or auto-detect when decoding text.
• Live mode. Enable “Convert as I type” to encode or decode instantly in the browser with no round-trip to a server.
• URL-safe Base64 (Base64URL). Use the Base64URL encoder/decoder for JWTs, tokens and filenames without escaping "+" or "/".
• MIME and PEM wrapping. Split lines at 76 or 64 characters when a mail client, certificate or OpenPGP tool expects wrapped output.
• Per-line encoding. On the text encoder, encode each line separately when you have multiple independent values.

Base64 decode and encode for developers

Developers use Base64 every day: embedding images in CSS and HTML, shipping binary in JSON APIs, reading JWTs, attaching files in MIME e-mail, and storing keys in PEM certificates. This free online Base64 decoder and encoder is built for that workflow—fast, accurate across standards, and private by default.

• Decode Base64 to text or file with automatic standard and charset detection, plus image/PDF/audio/video preview.
• Encode text, files or URLs to Base64 with UTF-8 and 35+ character sets, MIME line wrapping and Base64URL.
• Validate, repair and normalize messy Base64 from logs, e-mail and copy-paste with dedicated developer tools.
• Language guides for JavaScript, Python, Java, Go, PHP, C#, Node.js and Bash so you can match what your code produces.

Safe, free and private

All conversions run over HTTPS. Text and local files are converted in your browser with JavaScript—they are not uploaded or stored. The site is free to use with no account and no software to install. Optional remote URL fetching and a few network tools use our API; those responses are not kept for inspection.

AI assistants: ChatGPT, Claude, Grok & Cursor

Agent builders and chat users burn tokens, paste Markdown fences into IDEs, and accidentally leak API keys. Fix those pains locally—then verify any Base64 the model invents.

• Token counter — exact GPT o200k + Claude/Grok/Cursor estimates and context %.
• LLM text cleaner — strip ``` fences or flatten Markdown from bot answers.
• Secret redactor — scrub keys/JWTs before pasting into any bot.
• Verify Base64 — catch LLM hallucinations with a real decode round-trip.

Bộ đếm token AI · Limpiador de texto LLM · Redactor de secretos · Verificar Base64 · AI tools guide

PDF form filler — insurance, medical & corporate

Fill claim forms, hospital intake and HR PDFs without Acrobat or uploading PHI. Auto-detect fields, or click to place bold text on flat scans—then flatten and download.

Điền biểu mẫu PDF · Gộp PDF · Insurance & medical guide

Converters people search for (bytes, hex, CSV, color)

Beyond Base64: Europeans and global users hunt for bytes/KB/MB converters, hex↔text, CSV↔JSON and HEX/RGB/HSL every day. Drop a PDF to see exact bytes—all private in the browser.

• Bytes converter — KB/MB/GB/TB + KiB/MiB; PDF/file → exact bytes.
• Hex / binary / ASCII — text dumps and number bases 2/8/10/16.
• CSV ↔ JSON — auto-detects European semicolon exports.
• Color converter — HEX ↔ RGB ↔ HSL with live swatch.

Bytes converter · Hex converter · CSV ↔ JSON · Color converter

Developer & IT toolkit (daily corporate searches)

Engineers live in browser tabs: regex on logs, cron next-runs, config diffs, CIDR math, YAML↔JSON for Kubernetes. All of these run locally here—safe when policy forbids pasting secrets into random SaaS.

• Regex tester — live highlight + presets (email, IP, UUID).
• Cron explainer — plain English + next fire times.
• Diff checker — compare configs / API responses privately.
• CIDR subnet calculator — VPC and firewall planning.
• YAML ↔ JSON — K8s, GitHub Actions, Ansible.

Trình kiểm tra regex · Explicador de cron · Comparador de texto (diff) · Calculadora de subred · YAML ↔ JSON · Dev/IT guide

Christmas 2026: Secret Santa & countdown (high season)

From November through Christmas Eve, millions search for Secret Santa generators and “days until Christmas.” Draw Amigo Secreto privately with Base64URL links—no email signup—and keep a live countdown on your device.

• Secret Santa / Amigo Secreto — fair draw, couple exclusions, pass-the-phone or private WhatsApp links.
• Christmas countdown — how many days until Dec 25 in your timezone.

Trình tạo Ông già Noel bí mật · Đếm ngược Giáng sinh · Christmas traffic guide

Save bandwidth: compress before Base64

Where mobile data is expensive—Brazil, LATAM and other prepaid markets—uploading a huge photo just to shrink it wastes the plan. Compress locally first, then encode or share once.

• Compress images to WebP/JPEG in your browser, see % saved, then download or copy Base64—no upload.
• Gzip text or JSON before Base64 for APIs; decompress payloads you receive.
• Private by design — Canvas and CompressionStream run on your device.

Nén ảnh · Gzip comprimir / descomprimir · Compress before Base64 · Save mobile data guide

Private media tools (not social downloaders)

We will not scrape Instagram, LinkedIn, Pinterest or Kuaishou. We do help you prepare files you already own: convert HEIC/WebP, merge PDFs, cut out backdrops, build favicons—entirely in the browser.

• HEIC / WebP / SVG converter — iPhone photos and WebP downloads without uploading to Adobe/Canva-style sites.
• Merge PDF — combine contracts or turn images into a PDF locally (no Smallpdf upload).
• Remove background from product shots and logos (solid/near-solid backdrops).
• Favicon generator — PNG sizes, HTML tags and webmanifest, plus Base64 copy.

Trình chuyển đổi ảnh · Gộp PDF · Quitar fondo · Generador de favicon · HEIC & WebP guide

Built from real Reddit gaps (not Base64-only)

Users on Reddit keep asking for tools that never upload files: strip GPS EXIF, hash checksums, JSON formatters without ads, QR codes without tracking short links. We ship those here—private, free, and ranked for EU and US search.

• Strip EXIF before posting photos.
• Hash, JSON, UUID, timestamp, password, QR — everyday utilities that stay on-device.

Strip EXIF · Tạo hash · Định dạng JSON · QR generator · Reddit gap write-up

Base64 reader: paste and see

Need a live Base64 viewer? Paste a string or data URI and read the result immediately—text, image, PDF or hex—or get Base64 output as you type plain text. No Decode click required.

Trình đọc Base64 · Why live readers win

Built for the AI era

ChatGPT and Claude often invent Base64 that looks right but is wrong. AI agents double-encode payloads and burn context on huge Base64 blobs. This site’s principle: never trust a model to be the encoder—verify with a real tool in your browser.

• Verify Base64 from LLM output with round-trip checks before you ship a header or JWT.
• Unwrap nested Base64 when an agent or gateway encoded twice.
• URL encode/decode beside Base64URL for safe query strings.
• Principles for agents and MCP: deterministic tools, privacy, right dialect, watch token cost.

Verificar Base64 · Desenvolver Base64 anidado · AI agent guide · Why ChatGPT fails at Base64