image-tools

Image Format Converter

Decode one browser-readable JPG, PNG, WebP, or GIF static bitmap and request a new PNG, JPEG, or WebP encoding without changing pixel dimensions.

Tool workspace

The interactive tool requires JavaScript.

Instructions

Choose a file this browser can decode and verify that width and height are each between 1 and 16384 pixels.
Choose PNG, JPEG, or WebP. Use quality only as an encoding hint for JPEG or WebP; PNG disables that control.
Generate the output and verify actual MIME, unchanged pixel dimensions, background/transparency, visible artifacts, destination acceptance, and bytes before download.

Select an image, choose an output encoding, generate from the original selection, and download only when the returned Blob MIME matches that choice. The AIGClub handler performs this conversion with browser Canvas APIs.

Direct answer

Image Format Converter decodes the originally selected static bitmap and re-encodes the same width and height as PNG, JPEG, or WebP. It does not merely rename the file. Each conversion starts from the source selection, not the previous preview; JPEG output is drawn over white in this implementation. If the browser falls back to another MIME, the tool reports the mismatch instead of giving the file a misleading extension.

Local file safety limits

Choose one GIF, JPEG, PNG, or WebP file no larger than 20 MiB. Width and height must each be 1–16384 pixels, decoded area must not exceed 16,777,216 pixels, and estimated working memory must not exceed 256 MiB. The browser validates the declared MIME, file signature, decoded bitmap, requested output MIME, and output dimensions.

Output limits

Canvas export can change metadata, EXIF, ICC profiles, orientation handling, animation, transparency, color, and lossy quality. Keep the original and inspect every downloaded output in its destination.

How to use this tool

  1. Choose a file this browser can decode and verify that width and height are each between 1 and 16384 pixels.
  2. Choose PNG, JPEG, or WebP. Use quality only as an encoding hint for JPEG or WebP; PNG disables that control.
  3. Generate the output and verify actual MIME, unchanged pixel dimensions, background/transparency, visible artifacts, destination acceptance, and bytes before download.

Worked example: transparent PNG to JPEG

Select a 1200 × 800 PNG with transparent corners, choose JPEG, and generate. The summary should remain 1200 × 800 and report image/jpeg. This implementation paints white before drawing the source for JPEG; inspect every formerly transparent edge and compare text or logo detail at the destination.

A conversion changes encoding, not dimensions

The Canvas is created at the decoded source width and height. To change composition or scale, crop or resize first. A 2400 × 1600 input stays 2400 × 1600 here even when its MIME and encoded byte count change.

Every attempt uses the source selection

After a PNG, JPEG, or WebP result is shown, changing format or quality invalidates the old download and restores the source preview. The next generation redraws the independent source Image, preventing repeated lossy conversions or accidental alpha loss from becoming the new input.

MIME and browser capability check

Canvas may be unable to produce a requested format. The handler compares Blob.type with the selection and derives the extension from the matching Blob only. Browser versions, operating systems, encoders, memory, and receiving applications remain variables; no universal WebP or fixed-size promise is made.

Metadata, animation, color, and local scope

The tool makes no guarantee that EXIF, other metadata, ICC profiles, animation, or color interpretation will be removed or retained. Its handler uses object URLs, Image, Canvas, Blob, and a download link without an application upload call; that does not mean the entire page or device is offline or private.

Frequently asked questions

Why did the tool reject a WebP request instead of downloading PNG?

The returned Blob MIME did not match image/webp. Rejecting the fallback prevents a PNG payload from receiving a .webp name.

Can converting to JPEG make transparent areas predictable?

This implementation fills the Canvas white before JPEG encoding, but you must still inspect antialiased edges and the final recipient rendering.

Does choosing quality 1 make JPEG lossless?

No. The value is a browser encoder hint and does not turn JPEG into a lossless workflow or guarantee original pixels.

Will converting the same source twice compound compression?

Not within one selection. Each Generate action redraws the original static source rather than the previously exported preview.

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