Base64 afkod og kod online

Hvorfor bruge denne Base64-konverter?

• Privat fra starten. Din tekst og dine filer behandles lokalt med JavaScript. Selv store eller fortrolige filer forlader aldrig din enhed.
• Klarer Base64 fra den virkelige verden. Data-URI'er, linjeskift, URL-sikre tegn og manglende padding accepteres automatisk, og fejl peger på det præcise tegn.
• Alle standarder. Standard RFC 4648, Base64URL, MIME, PEM, IMAP, XML og OpenPGP armor.
• Alle tegnsæt. UTF-8, UTF-16, Windows-125x, ISO-8859-x, Shift_JIS, GBK, Big5, EUC-KR, KOI8 og flere.
• Output klar til indsættelse. Få en data-URI, CSS-regel, HTML-tag eller et JSON- eller XML-udsnit i stedet for en bar streng.

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.

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.

Regex tester · Cron explainer · Diff checker · Subnet calculator · 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.

Secret Santa generator · Christmas countdown · 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.

Compress image · Gzip compress · 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.

Image converter · Merge PDF · Remove background · Favicon generator · 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 · Hash generator · JSON formatter · 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.

Base64 reader · 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.

Verify Base64 · Unwrap nested Base64 · AI agent guide · Why ChatGPT fails at Base64

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.

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.

Sådan virker Base64 på 30 sekunder

Base64 tager tre bytes (24 bit) ad gangen, deler dem op i fire grupper på 6 bit og knytter hver gruppe til et af 64 tegn. For eksempel bliver ordet Man (bytes 77 97 110) til TWFu. Læs algoritmen trin for trin, eller start med Hvad er Base64?

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.