PNG to Base64 Converter: Free, Private, No Upload

Convert PNG files to Base64 in your browser. Smaller output file, batch up to 20 files at once, no upload, no account, no watermark. Your files never leave your device.

PNG to Base64
Batch up to 20 files
No upload, no account
Metadata stripped

1Add up to 20 images
2Pick from 18 formats
3Download or copy the code

Processed on your device. Your images are never uploaded, and metadata is stripped. How we keep it private

How do I convert PNG to Base64 for free?

Drop your PNG files into the tool above, choose Base64 as output, and download the result. Everything runs in your browser, so nothing is uploaded and there is no limit or watermark. It works on Windows, Mac, Linux, ChromeOS, iOS and Android — anywhere you have a modern browser.

Price: Free, no credits and no daily cap
Account required: No
File uploaded to server: No, processed locally in your browser
Batch limit: Up to 20 files at once
Input format: PNG
Output format: Base64
Best for: Base64 workflows, smaller files, faster sharing
Works on: Chrome, Edge, Firefox, Safari, iOS and Android browsers
Privacy: No upload, no tracking, metadata stripped
Output quality: Adjustable 1-100, defaults to 90

How to convert PNG to Base64

1
Drop your PNG files
Drag up to 20 PNG files onto the page or click to choose them. Everything runs in your browser.
2
Base64 is preselected
Output is already set to Base64. Adjust quality, resize or batch if you want.
3
Download
Save each Base64, or download all of them together as a ZIP.

PNG to Base64: what changes and when it makes sense

PNG is a Portable Network Graphics format. It is best known for exact pixel reproduction, crisp text and edges, and full alpha transparency. The main drawbacks are large files for photographs and no lossy mode for trading quality against size.

Base64 is not an image format. It is a Base64 encoded text that wraps the image data as text. Its main appeal is moving binary image data through JSON, databases and other text-only channels. The main drawbacks are a size about a third larger than the original and no way to preview it without decoding.

PNG vs Base64 at a glance

Property	PNG	Base64
Type	Raster image	Text encoding of an image
Compression	Lossless (DEFLATE), with an optional 8-bit palette mode	The image bytes are written out as Base64 text, which adds about 33 percent to the size
Transparency	Full alpha channel with soft edges	Same as the embedded image
Animation	No	Same as the embedded image
Colour depth	8 or 16 bits per channel, or 8-bit indexed colour	Same as the embedded image
Support	Opens in every browser and image editor	Plain text, so it travels through any system that handles strings
History	Created in 1995 as a free, patent-unencumbered replacement for GIF after Unisys began charging royalties for LZW compression. Became a W3C Recommendation in 2003. The signature bytes are 89 50 4E 47 0D 0A 1A 0A — "PNG" with newlines designed to catch file corruption.	Base64 encoding originated in the 1980s for encoding binary data in email (MIME). Standardised as RFC 4648 in 2006. It maps 3 bytes of binary to 4 ASCII characters using a 64-character alphabet.

What actually changes in this conversion

Base64 is an encoding of the image data, not a new compression scheme. The text is about a third larger than the binary file, so what you gain is portability rather than a smaller size.
Transparency follows the image data being encoded. Base64 itself is only a text wrapper.
EXIF, GPS and camera data are stripped on every conversion. That is good for privacy, but you lose capture dates.

About PNG: history and technical details

Created in 1995 as a free, patent-unencumbered replacement for GIF after Unisys began charging royalties for LZW compression. Became a W3C Recommendation in 2003. The signature bytes are 89 50 4E 47 0D 0A 1A 0A — "PNG" with newlines designed to catch file corruption.

Technical: Uses DEFLATE (LZ77 + Huffman) compression. Two main modes: 8/16-bit truecolour with alpha, and 8-bit indexed with up to 256 colours. Filters per scanline (None, Sub, Up, Average, Paeth) before DEFLATE for better ratios.

Real-world size: A 1920x1080 screenshot is 200-600 KB as PNG. As JPG at quality 85 it is 100-300 KB but with blurry text. A 12-MP photo is 18-25 MB as PNG, 2-4 MB as JPG. PNG wins on text, JPG wins on photos.

Popular tools: Adobe Photoshop, GIMP, Figma, Sketch, Snipping Tool, macOS Screenshot, ImageMagick, pngquant, oxipng.

Alternatives: WebP lossless (20-30% smaller), AVIF (better for photos), JPG (photos only), SVG (vector graphics).

About Base64: what you get

Base64 encoding originated in the 1980s for encoding binary data in email (MIME). Standardised as RFC 4648 in 2006. It maps 3 bytes of binary to 4 ASCII characters using a 64-character alphabet.

Technical: Encodes every 3 bytes as 4 base64 characters. Padding uses "=" characters. Uses A-Z, a-z, 0-9, + and /. URL-safe variant replaces +/ with -_ and omits padding. Output size is ceil(n/3)*4 bytes (33% overhead).

Real-world size: A 1 MB image becomes ~1.33 MB as base64. A 100 KB thumbnail becomes 133 KB. JSON payloads with base64 images are much slower to parse than equivalent binary uploads.

Popular tools: Node.js Buffer, Python base64 module, Postman, curl --data, any modern language standard library.

Alternatives: Multipart/form-data (binary upload), Object storage + URL, Data URL (with mime prefix), Signed URLs.

Browser and software compatibility

PNG: Opens in every browser and image editor. Base64: Plain text, so it travels through any system that handles strings.

Base64 is plain text, so it works anywhere strings are accepted.

Why people move away from PNG

A PNG of a photograph is commonly several times larger than the same image as JPG or WebP, which hurts page weight.
Screenshots and photos exported as PNG are among the heaviest assets on many sites.
Some upload forms and print services reject PNG or downscale it aggressively.

Why people choose Base64

Base64 is plain text, so the image can travel through JSON APIs, databases and text-only channels.
Many APIs, including OCR, vision models and email services, accept images as Base64 strings.

Common mistakes with PNG

Using PNG for photographs — files are 5-10x larger than JPG with no visible benefit
Saving screenshots as JPG by mistake — text becomes blurry and unreadable
Forgetting PNG transparency — white backgrounds appear where there should be alpha

Best practices for keeping quality

PNG sources often contain transparency. Decide before converting what should replace it: white, black or a brand colour.
Check whether your API wants the raw Base64 string or a full data URL with the data:image prefix. They are not interchangeable.
Base64 expands data by about a third. For large images, upload the file to storage and send a URL instead.
Resize before converting if the image will be shown small. A 4000 pixel photo displayed at 800 pixels wastes bytes in any format.
Check the result at 100 percent zoom, especially around text, edges and gradients, before you replace any originals.
Keep your original files. Conversions to a lossy format cannot be undone.
When you convert a set of images, use the same quality setting for the whole batch. The converter handles up to 20 files at once.

PNG to Base64 questions

Quick answers about privacy, quality, supported formats, file limits and how Base64 works.

Why convert PNG to Base64?

Base64 files are typically smaller than PNG, which makes them faster to share, send and load. The trade-off is a small amount of image detail at low quality settings.

Will converting PNG to Base64 lose quality?

At 90% quality, most people cannot tell the difference. Use 85-95% for photos and you are fine.

Does Base64 keep transparency?

Base64 is only a text wrapper around the image data, so transparency depends on the image format inside it.

Are my files uploaded?

Never. Everything runs in your browser. Your files never leave your device. Open DevTools Network tab while processing — you will see no upload request.

Can I convert many files at once?

Yes, up to 20 files at once. Download them individually or all together as a ZIP.

Does the converter strip metadata?

Yes. Browsers do not pass EXIF data through a canvas, so GPS, camera model and dates are removed on every conversion. That is good for privacy.

Is it free?

Yes. No credits, no daily cap, no account, no watermark. The practical limit is your device memory.

What is the difference between Base64 and Data URL?

Base64 is just the encoded string. A Data URL includes the mime type prefix (data:image/png;base64,). Some APIs want the raw string, others want the full Data URL — always check the API docs.

Your files never leave your device

No upload, no account, no tracking. Everything happens in your browser using the Canvas API and WebAssembly. You can confirm this in your browser's DevTools Network tab while the tool runs — no request carries your file. See why ToolDeck is different.