About

Telegram stickers use the WebP format - a lossy/lossless image codec developed by Google. Most image editors, presentation tools, and print workflows do not accept WebP. If you paste a .webp file into a document expecting .png, you get a broken placeholder or silent data loss. This tool decodes any browser-supported image (WebP, BMP, SVG, GIF, AVIF) and re-encodes it as a lossless PNG using the native Canvas API. No file leaves your device. Processing happens entirely in-memory via HTMLCanvasElement.toBlob(). Limitation: animated .tgs (Lottie) stickers require decompression of a gzipped Lottie JSON, which this tool does not perform. Static .webp stickers are fully supported.

Formulas

The conversion pipeline follows a three-stage rasterization process:

decode(file) → img_rgba → canvas.drawImage(img, 0, 0) → canvas.toBlob(cb, "image/png")

Where file is the raw input bytes read via FileReader.readAsDataURL. The browser's native image decoder produces an RGBA bitmap img_rgba with dimensions w × h. The canvas is sized to match:

canvas.width = img.naturalWidth , canvas.height = img.naturalHeight

Output file size depends on the PNG deflate compression of the raw pixel data. For an image with w × h pixels, uncompressed RGBA data occupies:

S_raw = w × h × 4 bytes

Where S_raw is the uncompressed payload size. PNG compression typically achieves 30 - 70% reduction depending on image complexity. Telegram static stickers are fixed at 512 × 512 px, yielding S_raw = 1,048,576 bytes (≈ 1 MB).

Reference Data

Input Format	MIME Type	Transparency	Animation	Browser Support	Conversion
WebP (Static)	image/webp	Yes (Alpha)	No	Chrome, Firefox, Edge, Safari 14+	Full
WebP (Animated)	image/webp	Yes	Yes	Chrome, Firefox, Edge	First frame only
PNG	image/png	Yes (Alpha)	APNG possible	Universal	Pass-through
JPEG	image/jpeg	No	No	Universal	Full (adds white bg)
BMP	image/bmp	Limited	No	Universal	Full
GIF (Static)	image/gif	1-bit	No	Universal	Full
GIF (Animated)	image/gif	1-bit	Yes	Universal	First frame only
SVG	image/svg+xml	Yes	Possible	Universal	Rasterized at native size
AVIF	image/avif	Yes	Possible	Chrome 85+, Firefox 93+	Full where supported
ICO	image/x-icon	Yes	No	Most browsers	Full
TIFF	image/tiff	Yes	No	Safari only	Safari only
TGS (Lottie)	application/gzip	Yes	Yes	None (needs decoder)	Not supported
Output: PNG	image/png	Yes (32-bit RGBA)	No	Universal	-

Frequently Asked Questions

The browser's native element decodes animated WebP and GIF formats but canvas.drawImage() captures only the current (first) frame at render time. Extracting all frames requires parsing the WebP container's ANMF chunks or GIF's frame table - a non-trivial binary operation. For animated Telegram stickers in .tgs format (gzipped Lottie JSON), a dedicated Lottie renderer would be required. This tool handles static stickers and single-frame conversion only.

Yes. The canvas is initialized without any background fill, preserving the full 32-bit RGBA data. PNG supports 8-bit alpha channels natively. If your source image is JPEG (which has no alpha), the output PNG will have a fully opaque alpha channel - no artificial transparency is added.

There is no hard limit imposed by this tool, but browser memory constraints apply. A 4096×4096 pixel image requires approximately 64 MB of raw RGBA data in canvas memory. Most devices handle images up to 8000×8000 pixels comfortably. Beyond that, some browsers (especially mobile Safari) may silently fail or produce a blank canvas. The tool validates dimensions before processing.

PNG output is lossless with respect to the decoded pixel data. However, if the source WebP used lossy compression, the original encoding artifacts are already baked into the pixel data. You recover the full fidelity of the decoded bitmap but cannot reverse the lossy compression. For lossless WebP sources, the PNG output is pixel-identical.

Yes. The tool accepts multiple files via the file picker or drag-and-drop. Each file is processed sequentially through the canvas pipeline. All converted PNGs appear in the results area with individual download buttons plus a "Download All" option that packages them into sequential downloads.

WebP typically achieves 25-34% better compression than PNG for equivalent visual quality (per Google's comparative study). When converting WebP→PNG, file size increases because PNG's DEFLATE compression is less efficient than WebP's VP8/VP8L codec. A 50 KB WebP sticker may become 120-200 KB as PNG. This is expected and unavoidable without lossy re-compression.