> PNG | encode | data-uri <
// Encode PNG images to Base64 strings and data URIs — alpha transparency preserved, runs entirely in your browser
Drop PNG here or click to select
Click to browse PNG files
Alpha Preserved
PNG alpha channel, palette, and gAMA/tRNS chunks encode byte-for-byte — no re-compression, no quality loss.
100% Client-Side
Your PNG never leaves the browser. Encoding happens locally via FileReader + btoa() — no server round-trip.
Copy & Paste
Get a standards-compliant data:image/png;base64,… URI ready for HTML, CSS, emails, JSON payloads, and inline SVGs.
// FAQ — PNG TO BASE64
Q: What is PNG to Base64 encoding?
A: It converts the binary contents of a .png file into an ASCII string using the Base64 alphabet defined in RFC 4648. The encoded text can be dropped directly into an HTML <img> tag, a CSS background-image, an email message, a JSON API payload, or any other text-only transport. The PNG bytes themselves are unchanged — every IHDR, IDAT, tRNS, and IEND chunk is encoded and can be recovered exactly.
Q: How do I encode a PNG to Base64 in the browser?
A: Drag your PNG into the drop zone (or click to browse). The tool reads the file with FileReader.readAsDataURL(), which already returns a ready-to-use data:image/png;base64,… URI. Choose Data URI if you want to paste it directly into <img src="…">, or Base64 payload only if your API/database expects the raw Base64 portion without the data:image/png;base64, prefix.
Q: Does encoding a PNG to Base64 lose transparency or quality?
A: No. Base64 is a pure binary-to-text transform — every byte in the original PNG is preserved, including the alpha channel, palette, and color profile (iCCP/sRGB chunks). When you decode the string back, the file is bit-identical to the original. A SHA-256 hash of the decoded PNG will match the original. That is why Base64 is the correct tool for embedding icons, logos, and screenshots where pixel accuracy matters.
Q: How much larger does a PNG get after Base64 encoding?
A: Base64 uses 4 characters for every 3 input bytes, so the encoded string is ~33% larger than the original PNG file. The exact size is 4 × ⌈n / 3⌉ characters, where n is the PNG size in bytes. A 10 KB PNG becomes ~13.6 KB of Base64 text. Because HTTP compression (gzip, Brotli) handles Base64 text fairly well, the over-the-wire overhead is usually closer to 10–15% in practice.
Q: What does a Base64-encoded PNG look like?
A: Every PNG Base64 string begins with iVBORw0KGgo. That prefix is the 8-byte PNG signature 89 50 4E 47 0D 0A 1A 0A re-encoded to Base64. So iVBORw0KGgoAAAANSUhEUg... is always a PNG, and seeing that prefix is a quick visual check that your data is intact. When wrapped as a data URI it looks like: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8/5+hHgAHggJ/PchI7wAAAABJRU5ErkJggg==
Q: How do I embed a PNG as Base64 in HTML?
A: Paste the full data URI into the src attribute of an <img> tag: <img src="data:image/png;base64,iVBORw0KGgo…" alt="logo">
The browser decodes the Base64 payload and renders the PNG exactly as if it were loaded from a URL. No extra HTTP request is made, which is useful for critical-path icons, email signatures, and offline-first apps.
Q: How do I use a Base64 PNG as a CSS background?
A: Wrap the data URI in the url() function: .icon { background-image: url('data:image/png;base64,iVBORw0KGgo…'); }
For reuse, store it in a CSS custom property: :root { --logo: url('data:image/png;base64,iVBORw0KGgo…'); } .brand { background: var(--logo); }
Inline backgrounds eliminate one HTTP request per icon but bloat your CSS file, so use them for small icons (< 4 KB) only.
Q: How do I encode PNG to Base64 in JavaScript / Node / Python / PHP?
A:
JavaScript (browser): const uri = await new Promise(r => { const f = new FileReader(); f.onload = () => r(f.result); f.readAsDataURL(pngFile); });
Node.js: fs.readFileSync('logo.png').toString('base64')
Python: import base64; base64.b64encode(open('logo.png','rb').read()).decode()
PHP: base64_encode(file_get_contents('logo.png'))
Go: base64.StdEncoding.EncodeToString(pngBytes)
Ruby: Base64.strict_encode64(File.read('logo.png'))
Q: When should I use a Base64 PNG instead of a normal image file?
A: Use Base64 PNG data URIs when:
• the image is < 4 KB (to save an HTTP round-trip)
• you need to embed it inside an HTML email (many clients block remote images)
• you are shipping a single-file HTML report or dashboard
• you are storing the image inside a JSON payload or a database column
Prefer an external .png file when the image is large, reused across many pages, or needs separate CDN caching.
Q: Does Base64 encoding work with PNG transparency and palette PNGs?
A: Yes. Because Base64 is a bit-for-bit transform, every PNG color mode is supported equally:
• RGBA / truecolor + alpha — 32-bit color, full transparency
• Palette (PLTE) + tRNS — indexed palette PNGs with 1-bit transparency
• Grayscale + alpha — 8/16-bit grayscale with alpha
• 16-bit deep color PNGs — HDR-style PNGs used in medical imaging and scientific visualisation
All of these round-trip cleanly through Base64 and display correctly in browsers that understand PNG.
Q: Is a Base64-encoded PNG encrypted or private?
A: No. Base64 is an encoding, not encryption. Anyone who can read the string can decode it back to the original PNG in milliseconds. If a screenshot contains a password, an API token, or personal information, encoding it as Base64 does not protect it — use a real encryption layer (AES-GCM, age, PGP) on top of the Base64 output, or transport the image over TLS to a server that applies access controls.
Q: What is the maximum PNG size I can encode here?
A: There is no artificial cap. Because encoding runs locally, the limit is your browser's memory — typically 100 MB+ on desktop and 40–60 MB on mobile. For very large PNGs (hi-res medical or satellite imagery), we read the file in chunks and call btoa() on each chunk so the main thread stays responsive. If your image is larger than ~100 MB, consider streaming it directly from a server-side encoder instead of loading it into the browser.
Q: PNG to Base64 vs JPG to Base64 — which should I use?
A: Use PNG → Base64 for logos, UI icons, screenshots, diagrams, and anything with transparency or sharp edges (text, charts). PNG is lossless and alpha-aware. Use JPG → Base64 for photographs or images with many colors where lossy compression is acceptable. JPEG files are typically 5–20× smaller than PNG for photos, so the Base64 payload is much shorter. As a rule of thumb: if the image came from a camera or contains photographic gradients, use JPG; otherwise PNG.