Image Converter

Format Mismatch Is a Real Problem — Here's the Fix

A client sends a logo as a JPG with a white box around it. Your CMS only accepts PNG. Your Shopify theme requires WebP for performance scoring. A legacy print system only takes BMP. You've got a folder of PNGs that are loading slowly because photographic content compresses horribly in a lossless format. These are everyday situations where you need format conversion, not a full image editing workflow. The ToollyX Image Converter handles all of them: drop your files, pick the target format, download. The conversion happens in your browser using the same encoder that Chrome and Safari use natively — no server, no account, no file size limit beyond what your device can handle.

When to Choose Each Format

Convert to JPG when: the image is a photograph or photorealistic render; file size matters more than pixel-perfect accuracy; you need maximum compatibility with older software, email clients, or print workflows; you are removing a transparent background intentionally (transparency becomes white). Quality 80–85% is the practical sweet spot — visually indistinguishable from lossless for photographs at web display sizes. Convert to PNG when: the image contains flat colour areas, text, or line art that compress poorly in JPEG; you need to preserve a transparent background; you are creating a lossless working copy before further editing. Convert to WebP when: the image will be served on a website; you want JPEG-level file size with PNG-level transparency support; your target audience uses modern browsers (Chrome, Firefox, Safari, Edge — all support WebP natively). WebP consistently achieves 25–35% smaller files than equivalent-quality JPEG. Convert to BMP when: a specific Windows application, industrial system, or legacy tool only accepts uncompressed bitmap input.

What Happens to Transparency in Each Conversion

Transparency handling is the detail that trips people up most in format conversion. When converting a transparent PNG or WebP to JPG, transparent pixels are filled with white — JPG has no alpha channel and must fill every pixel with a colour. This tool does that fill explicitly so you get a white background rather than the artefacted black fill that some converters produce. When converting to WebP, transparency is fully preserved — WebP supports an alpha channel identical to PNG. When converting to PNG, transparency is preserved. When converting to BMP, transparency is lost (BMP is an uncompressed 24-bit format with no alpha support in browser canvas output). If you need transparent output on a coloured background rather than white, use the Transparent PNG Maker to remove the background first, then convert here.

Photographic PNG to WebP — the Highest-Impact Conversion

Many developers and designers save photographic content — hero images, blog photos, product shots — as PNG because it is lossless. A 3000×2000px photographic PNG from a camera is typically 4–12 MB. The same image as WebP at quality 85 is typically 200–400 KB — a 10–30× reduction — with no visible quality difference at web display sizes. This single conversion type is responsible for more page speed improvements than almost any other optimisation. Run your existing PNG image library through the batch converter set to WebP, then replace the files on your server. Use the Image Compressor if you want to additionally tune the quality level or apply a max width constraint at the same time.

GIF Source Files — What to Expect

GIF files can be uploaded as source material but the conversion output is a static image of the first frame only. The HTML5 Canvas API does not decode GIF animation frames — it reads the first frame as a static image and draws that to the canvas. If you upload an animated GIF and convert to WebP, you get a static WebP of frame one, not an animated WebP. For animated GIF processing, the GIF Frame Viewer lets you inspect individual frames before deciding which one to extract. For creating animated output from a set of images, that workflow is outside browser-based canvas conversion and requires a dedicated tool.

Batch Converting a Full Image Library

Drop multiple files at once — the converter processes them in parallel and shows individual before/after file size comparisons for each file. The original filename is preserved with the new extension appended: product-shot.png becomes product-shot.webp. This makes replacing files in an existing asset structure straightforward — the filenames match, only the extension changes. If you later change the target format or quality, the Reconvert All button re-processes every loaded file with the updated settings without needing to re-upload. After converting, if specific pixel dimensions are also needed, run the converted files through the Image Resizer.

✓Verified by ToollyX Team · Last updated June 2026