Base64 encode & decode the right way
Paste text, drop a file or a JWT. B64Nex detects what it is, encodes and decodes Base64 with every charset (UTF-8, TIS-620, Windows-874 …), URL-safe and MIME options, shows exactly where invalid Base64 breaks, previews decoded images and PDFs and shares a read-only link in one click.
Try it now — no sign-in needed
Paste text, Base64 or a JWT, drop any file, keep up to 20 documents in this browser and share a read-only link with anyone.
From mystery strings to clear data in a second
Built for developers, QA and support teams who read tokens, e-mail attachments, API payloads and certificates every day.
Knows what you pasted
Base64, Base64URL, MIME lines, data URIs, JWTs, hex and URL-encoded text are detected as you paste; decoded bytes are identified by their magic bytes and previewed – images, PDF, audio, video or text.
Thai charsets
UTF-8, TIS-620, Windows-874, UTF-16/32, ISO-8859, Windows-125x and CJK – match any legacy system byte for byte.
Exact error position
Strict validation names the bad character, its line and column, and jumps right to it.
Files & images
File → Base64, data URI, <img> or CSS; Base64 → file with the right extension. 20 MB files stay smooth.
JWT, URL, Hex, Base32, hashes
Decode JWT claims with expiry, URL / HTML entities, hex dumps, Base32 and MD5 / SHA-1 / SHA-256 / SHA-512.
Cloud library
Snippets in folders and tags, full-text search (also inside decoded text), versions, history and a 30-day trash.
Private by design
Tools run in your browser. Keycloak sign-in, encrypted storage and PDPA export or erasure any time.
Three steps
Paste or drop
Paste text, Base64 or a JWT, or drop any file – images, PDF, certificates.
Encode or decode
Pick charset, URL-safe, MIME lines or per-line mode; live mode shows the result while you type.
Copy, download, share
Copy the result, download the decoded file with the right extension or send a read-only link.
Rent B64Nex monthly or yearly
Start free. Upgrade when you need more space and bigger files. Cancel any time.
Prices in Thai baht including 7% VAT. Tax invoices are issued automatically.
Frequently asked questions
Do I need an account?
No. Every encoder, decoder and converter runs in your browser and keeps up to 20 documents on this device. Sign in to keep snippets in your cloud Library with history and versions.
How does billing work?
Choose a plan and pay monthly or yearly by PromptPay or card. Yearly plans cost 10 months. You get a tax invoice for every payment and can cancel any time — the plan stays active until the end of the period.
Is Base64 encryption?
No. Base64 only changes how bytes are written; anyone can decode it. Never treat Base64 of a password or token as a secret.
Who can see a shared link?
Anyone with the link can read the text and its decoded view – nobody can edit it. You can stop sharing at any time.
Which devices are supported?
All modern browsers on desktop, tablet and phone (installable as a PWA). Native iOS and Android apps are coming soon and sync with the same account.
Stop guessing what that string is
Encode, decode and preview in seconds. Upgrade when you're ready.
Try it now – free