Free Online Base64 Encoder — Text, Image & File to Base64
Encode text, images, and files to Base64 or a data URI. UTF-8 safe with a Base64URL option — no upload, no signup.
Encode a file or image to Base64
Convert any file (PNG, JPG, SVG, PDF, fonts…) to a Base64 string or data URI. The file stays on your device.
Quick answer
To encode text to Base64, paste it into the KaviForge Base64 Encoder and the Base64 output appears instantly. To convert an image or file to Base64, use "Choose file" to get both the raw Base64 string and a ready-to-use data URI (data:image/png;base64,…). Everything is processed in your browser.
This Base64 encoder turns strings, JSON payloads, images, and files into Base64 in your browser. Use standard Base64 or URL-safe Base64URL for tokens, data URIs, and APIs.
This encoder handles Unicode correctly by encoding text as UTF-8 first, so emoji and non-English characters round-trip without corruption. Enable URL-safe mode for Base64URL used in JWTs and URLs.
Related reading: What is a JSON Payload? A Simple Guide for API Beginners, Privacy-First Formatting: Why Our Online JSON Tool is 100% Safe, and How to Minify JSON (and Why It Makes Your Site Faster).
How to Use This Base64 Encoder
- 1Type or paste your text into the input box — the Base64 output updates as you type.
- 2Enable "URL-safe" if the result will be used in a URL, filename, or JWT.
- 3Enable "Wrap lines at 76 chars" for MIME/email-compatible output.
- 4To encode an image or file, click "Choose file" in the file section below.
- 5Copy the Base64 string or data URI, or download the output as a .txt file.
Features
Text to Base64
Live encoding as you type with full UTF-8 support for emoji and all languages.
Image & File to Base64
Encode PNG, JPG, SVG, PDF, fonts, or any other file type.
Data URI Output
Get a ready-to-paste data:…;base64 URI for HTML img tags or CSS backgrounds.
Base64URL Mode
Replaces + and / with - and _ and removes padding for URL-safe output.
MIME Line Wrapping
Optionally wrap output at 76 characters as required by email standards.
Private & Offline-Ready
Encoding happens locally in your browser — nothing is uploaded.
When to Use the Base64 Encoder
Embed an image in HTML or CSS
Convert small icons or logos to a data URI to inline them and save an HTTP request.
Send binary data in JSON or XML
APIs that only accept text can carry files and images as Base64 strings.
Create HTTP Basic Auth headers
Encode "username:password" to Base64 for an Authorization: Basic header.
Prepare email attachments
MIME email attachments are Base64 encoded with 76-character lines.
About the Base64 Encoder
The encoder uses the browser’s TextEncoder to convert text to UTF-8 bytes, then encodes those bytes with btoa in chunks so large inputs do not freeze the page.
Base64 is an encoding, not encryption — anyone can decode it. Base64 output is about 33% larger than the original data, so inline only small images.
Base64 Encoder FAQs
How do I encode text to Base64 online?
Paste your text into the input box of the KaviForge Base64 Encoder. The Base64 result appears instantly in the output box, ready to copy.
How do I convert an image to Base64?
Click "Choose file" in the "Encode a file or image to Base64" section and pick your image. You get the Base64 string and a data URI such as data:image/png;base64,… that you can paste into an img src or CSS url().
Does this Base64 encoder support UTF-8 and emoji?
Yes. Text is converted to UTF-8 before encoding, so emoji, accented letters, and non-Latin scripts encode correctly.
What is the difference between Base64 and Base64URL?
Base64URL replaces + with -, / with _, and usually drops the = padding so the result is safe in URLs and filenames. JWTs use Base64URL.
Is Base64 encryption?
No. Base64 is a reversible encoding with no key. Never use it to protect passwords or secrets.
Are my files uploaded?
No. Text and files are encoded entirely in your browser and never leave your device.
Popular Base64 Encoder searches
- Encode a String to Base64Encode any text string to Base64 online. Paste your text and copy the result instantly. Supports UTF-8, free and processed in your browser.
- Base64 Encode UTF-8 Text and EmojiEncode Unicode text, accents and emoji to Base64 correctly. Avoid the btoa "Invalid character" error by encoding as UTF-8 first.
- Base64URL Encoder (URL-Safe Base64)Encode text to URL-safe Base64 (Base64URL) with - and _ instead of + and /, and no padding. The format used in JWTs and URLs.
- HTTP Basic Auth Header GeneratorGenerate an HTTP Basic Authorization header by Base64-encoding username:password. Build the header for curl, fetch and Postman.
- Encode JSON to Base64Encode a JSON object to Base64 for headers, query strings and config values. Paste JSON and copy the encoded string. Free and local.
- Base64 Encode in JavaScriptEncode a string to Base64 in JavaScript with btoa() in the browser or Buffer in Node.js. Check your result with the encoder before shipping.
- Base64 Encode a URLBase64 encode a URL to pass it safely as a parameter, hide it from casual reading or store it in a single token. Use Base64URL for safer links.
- Base64 MIME Encoding With 76-Character LinesMIME Base64 wraps lines at 76 characters. See what wrapped output looks like for email attachments and PEM-style data.
- Base64 Encode in PythonEncode a string to Base64 in Python with base64.b64encode. Remember to encode to bytes first and decode the result. Verify with the online encoder.
- Base64 Encoding Without PaddingEncode to Base64 without = padding characters. See when padding is optional, how to add it back, and why JWTs omit it.
Related Developer Tools
Base64 Decoder
Decode Base64 and Base64URL strings to text, or back to images and files. UTF-8 safe.
URL Encoder
Percent-encode text, query strings, and URLs. Choose component or full-URL encoding.
JWT Decoder
Decode JSON Web Tokens to read the header, payload, and claims, and check if a token has expired.
Related Guides & Tutorials
What is a JSON Payload? A Simple Guide for API Beginners
What is a payload in an API? See a sample JSON payload, payload JSON, and API payload examples — then format one with our free tool.
Privacy-First Formatting: Why Our Online JSON Tool is 100% Safe
Format or minify JSON without uploading a JSON payload. Our formatter is 100% client-side and private. Pretty print JSON securely now.
How to Minify JSON (and Why It Makes Your Site Faster)
Learn how to minify JSON to shrink payloads and speed up APIs. Use the free minifier — minify JSON in your browser in one click.