Image Format Converter

Conversion Receipt

{{ targetLabel }} {{ sourceInfo.width ? outputDimensionLabel : 'Sample ready' }} {{ sizingSummary }} {{ changeLabel }} {{ warnings.length }} note(s)

Source image:

Drop, paste, or browse one PNG, JPEG, WebP, GIF, SVG, AVIF, BMP, ICO, HEIC, HEIF, or other supported image.

Conversion settings continue below.

Ignored {{ ignoredCount }} extra file(s). This tool processes one image at a time.

Output settings

Target format:

Choose the downloaded file format. Native and custom encoder support is checked in the results.

Image sizing:

Choose whether conversion should preserve source dimensions or resize during export.

Output width:

Enter the maximum or exact output width in pixels.

Output height:

Enter the maximum or exact output height in pixels.

Fit behavior:

Controls how the source image sits inside the exact output canvas.

Scale: {{ safeScalePercent }}%

Use values below 100 for downscaling; enable upscale before using values above 100.

Allow upscale:

Keep off for sharper production assets; turn on when an exact larger canvas must be filled.

Resampling quality:

High is best for final output; low can be faster for very large local images.

Quality: {{ safeQuality }}%

Use 80-92 for clean web output; AVIF support depends on the browser encoder.

{{ alphaTargetLabel }} alpha handling:

Preserve transparency, or flatten decoded alpha onto a solid background before export.

Flatten color:

Pick the color painted behind transparent source pixels before export.

Icon set:

Choose the square PNG payloads written into the ICO container.

Icon size:

Choose the single square icon payload size written into the ICO container.

{{ matteLabel }} background:

Pick the matte color used when converting transparent PNG, WebP, SVG, GIF, or HEIC pixels to {{ matteLabel }}.

Waiting for a browser-readable image.

Metric	Value	Detail	Copy
{{ row.label }}	{{ row.value }}	{{ row.detail }}

Check	Status	Detail	Copy
{{ row.label }}	{{ row.value }}	{{ row.detail }}

Embed:

Customize

Include current inputs

Size

Advanced

Width

Height

Aspect ratio

Max height

Collapsible embed

Allow fullscreen

Referrer policy

Sandbox tokens

Image conversion changes the file that carries a picture, not just the name at the end of the file. A phone photo may arrive as HEIC, a screenshot may be PNG, a website may ask for WebP or AVIF, and an older application may still expect JPEG, BMP, or ICO. The same visible subject can survive the handoff while compression, transparency, dimensions, metadata, animation, and compatibility all change.

The first distinction is pixels versus format. Pixels are the decoded color grid. The format and codec decide how that grid is stored, compressed, labeled, and reopened. Renaming photo.png to photo.jpg does not convert the image. A real conversion decodes the source, optionally resizes or flattens it, then writes a new file in the target format.

Format choice is a practical tradeoff. PNG is usually best for screenshots, transparent artwork, and sharp interface graphics because it is lossless. JPEG is widely compatible for photos, but it cannot keep transparency and it discards detail at lower quality settings. WebP and AVIF can produce compact web images and can support transparency, but the receiving app or browser must support the chosen output. BMP is useful mainly when a legacy Windows workflow expects it, and ICO is a container for icon payloads.

Common image conversion choices and cautions
Job	Typical Direction	Main Caution
Share a phone photo with broad app support	HEIC or HEIF to JPEG or WebP	Metadata, depth data, bursts, and sidecars may not survive.
Prepare transparent artwork	PNG to PNG, WebP, AVIF, or ICO	Flattening alpha can create an unwanted matte edge.
Reduce web delivery bytes	JPEG or PNG to WebP or AVIF	Smaller bytes do not prove acceptable quality or support.
Create a favicon or desktop icon	Square artwork to ICO	Old readers may expect BMP-style icon entries.
Hand off to old software	Modern formats to JPEG or BMP	BMP output can become much larger than the source.

Size, quality, and compatibility must be judged together. A smaller file can still be a failed conversion if text becomes blurry, the aspect ratio changes, transparent pixels turn white, the receiver cannot open the format, or expected metadata disappears. The safest workflow chooses the target format for the receiver first, then checks dimensions, transparency, byte size, and preview quality as separate signals.

Some source features are not part of the still pixel grid. Animated GIF and animated WebP files may contain multiple frames. HEIC and HEIF files can carry image collections, sequences, derived images, depth maps, and Live Photo sidecars. A still-image conversion can produce a valid-looking preview while leaving those structures behind.

How to Use This Tool:

Use the converter for one source image at a time when the output needs a different format, size, canvas, transparency choice, or icon set.

Drop, paste, or browse one file in Source image. PNG, JPEG, WebP, GIF, SVG, AVIF, BMP, ICO, HEIC, HEIF, and other browser-decodable image files can be attempted, subject to local browser support.
Choose Target format. PNG, JPEG, WebP, AVIF, BMP, and ICO are available, and the result guidance reports whether the current browser produced the requested type.
Set Image sizing. Keep original dimensions for a format-only conversion, fit inside a maximum box, draw onto an exact canvas, or scale by percent.
For an exact canvas, choose Contain to keep the whole image with possible padding, Cover crop to fill the frame by trimming edges, or Stretch only when changed proportions are acceptable.
Leave Allow upscale off for sharper production assets. Turn it on only when a larger output frame is required and a softer result is acceptable.
Use Quality for JPEG, WebP, and AVIF. Values around 80 to 92 are often a reasonable web starting point, while PNG, BMP, and ICO do not use that lossy quality control here.
Choose alpha handling deliberately. JPEG and BMP flatten transparent pixels to a selected matte color. PNG, WebP, AVIF, and ICO can preserve alpha unless you choose to flatten it.
Review Converted Image, Conversion Metrics, Format Guidance, Byte Size Comparison, and JSON before downloading. Warnings identify geometry, metadata, transparency, animation, and encoder issues that can matter more than byte savings.

For ICO output, pick a preset that matches the destination. The favicon set uses 16, 32, and 48 px payloads; the app icon set uses 32, 48, and 256 px; the full set uses 16, 32, 48, 64, 128, and 256 px; and the single-payload option uses one selected square size.

Interpreting Results:

The conversion receipt summarizes output bytes, target label, dimensions, sizing mode, size-change direction, local-processing status, and warning count. A smaller byte count is only one signal. It does not prove that small text stayed sharp, transparency was preserved, metadata was retained, or the receiving application supports the output.

Converted Image is the visual proof. Inspect edges, lettering, crop, aspect ratio, color background, and transparent areas. For logos and UI artwork, check against the real background where the asset will appear. For photos, compare skin tones, fine texture, and compression artifacts before treating a size reduction as a success.

Image format converter result interpretation
Result Area	What It Shows	How to Use It
`Conversion Metrics`	Source type, target type, dimensions, quality, transparency, output file, and size change.	Use it as the audit trail for what changed before download.
`Format Guidance`	Encoder support, alpha behavior, metadata loss, animation loss, WebP facts, HEIC facts, and geometry warnings.	Resolve warning rows before handing the image to someone else.
`Byte Size Comparison`	A chart comparing source KB and output KB when both byte counts are known.	Use it for direction and proportion, then confirm quality in the preview.
`JSON`	A structured record of source facts, output facts, settings, support checks, warnings, and limits.	Copy it for QA tickets, documentation notes, or repeatable conversion records.

Many warnings are normal for valid conversions. JPEG and BMP are opaque in this workflow, so transparent pixels are painted over a matte. BMP is uncompressed and can be larger than modern web formats. ICO reports the square payload sizes it wrapped. SVG input is rasterized. Animated GIF and animated WebP inputs export as one still frame. WebP metadata chunks are not intentionally preserved.

HEIC and HEIF results need extra attention. The decoded still image may not include metadata, depth maps, bursts, image sequences, or Live Photo sidecars. A JPEG converted from HEIC may be easier to open but larger than the source, so reduce quality or choose a compact modern target when file size is the priority.

Technical Details:

Raster conversion follows a decode, transform, encode path. The source container is read into a still bitmap with width, height, and alpha information when available. Optional geometry steps resize the bitmap, place it inside a canvas, crop or pad it, and apply resampling. The encoder then writes a fresh file from the prepared pixels.

Pixel-based re-encoding should not be treated as metadata-preserving archival work. EXIF, GPS, XMP, embedded color profiles, frame timing, depth data, derived-image relationships, and sidecar context can live outside the drawn pixel grid. A conversion can be visually useful and still be unsuitable for evidence preservation, color-managed print work, or animation handoff.

Transformation Core:

Image conversion transformation stages
Stage	Mechanism	Evidence to Check
Decode	The browser or HEIC/HEIF decoder produces a still bitmap from the selected source file.	Source format, dimensions, WebP facts, HEIF brand facts, and source byte count.
Plan geometry	Original size, max-box size, exact canvas, or percent scale determines the output canvas and draw rectangle.	Output dimensions, sizing summary, crop warnings, stretch warnings, and upscale warnings.
Draw pixels	The decoded bitmap is drawn with the selected resampling quality into the planned output frame.	Preview sharpness, aspect ratio, crop position, and final pixel frame.
Handle alpha	Alpha-capable targets can preserve transparency; opaque targets and intentional flattening use a matte color.	Transparency rows, matte color warnings, and edge checks in the preview.
Encode	The prepared pixels are written as PNG, JPEG, WebP, AVIF, BMP, or ICO output.	Output MIME type, filename, byte count, support badge, download, and JSON record.

Sizing Formula Core:

For proportional resizing, a scale factor maps source dimensions to output dimensions. When upscaling is disabled, requested scale values above 1 are capped so the decoded source is not enlarged.

\begin{array}{lll} s & = & \min (\frac{W_{max}}{W_{source}}, \frac{H_{max}}{H_{source}}) \\ W_{output} & = & round (W_{source} \times s) \\ H_{output} & = & round (H_{source} \times s) \\ Size change % & = & \frac{B_{output} - B_{source}}{B_{source}} \times 100 \end{array}

For example, a 2400 x 1600 image fitted inside a 1200 x 900 box uses min(1200/2400, 900/1600) = 0.5, so the output becomes 1200 x 800. Exact canvas mode keeps the requested canvas size instead. Contain may add padding, cover may crop edges, and stretch may change proportions.

Target image format behavior
Target	Compression and Alpha	Best Fit	Limit to Verify
PNG	Lossless and alpha-capable	Screenshots, UI graphics, transparent artwork	Quality control is ignored because the output is lossless here.
JPEG	Lossy and opaque	Photos and broad compatibility	Transparent pixels are flattened to a matte color.
WebP	Lossy here and alpha-capable	Modern web images with compact output	Animated WebP sources export as one still frame.
AVIF	Lossy here and alpha-capable when supported	Compact modern web output	Unsupported browser encoders may return another format.
BMP	Uncompressed and opaque	Legacy Windows bitmap handoffs	Output bytes can grow sharply.
ICO	PNG icon payloads inside an ICO container	Favicons and desktop icons	Very old readers may expect BMP-style entries.

Browser-side safety limits keep oversized conversions from overwhelming the tab. Standard source files are capped at 40 MB, HEIC and HEIF files at 80 MB, output canvas area at 64,000,000 pixels, and output width or height at 12,000 px. The quality control is clamped to 40% through 100%, and the scale control can request 1% through 400% with enlargement blocked unless upscaling is allowed.

Privacy and Accuracy Notes:

The selected image is decoded and re-encoded in the browser after the page has loaded. The conversion does not upload the selected file for processing, but the browser's memory, decoder support, and encoder support determine whether a particular file can be converted.

Pixel-based output can remove EXIF, GPS, XMP, embedded color profiles, frame timing, depth information, sidecars, and application metadata.
Animated GIF and animated WebP sources export as one decoded still frame.
SVG sources are rasterized to decoded display dimensions before output.
AVIF output depends on the current browser encoder and may fall back to another type when unsupported.
HEIC and HEIF files depend on browser-side decoding and may lose collection, sequence, burst, depth, and Live Photo context.

Worked Examples:

Transparent PNG to WebP:

A 960 x 540 transparent PNG exported to WebP at 88% quality with original dimensions should remain 960 x 540. Keep alpha preserved and inspect the preview on a light and dark background before downloading, because transparent edges can look acceptable on one matte and poor on another.

Phone HEIC to JPEG:

A 4032 x 3024 HEIC photo converted to JPEG at 85% quality becomes easier for older apps to open, but it may grow larger than the HEIC source. Check the byte-size comparison and guidance rows, then decide whether compatibility or file size matters more for that handoff.

Square Logo to ICO:

A 512 x 512 transparent logo converted to the full ICO set should report payloads at 16, 32, 48, 64, 128, and 256 px. The PNG-payload warning is expected. Test the resulting icon in the destination application when compatibility with very old readers matters.

FAQ:

Does the image get uploaded?

No upload is made for the selected image during conversion. It is decoded and re-encoded in the browser after the page loads, subject to local memory and format support.

Why did AVIF return another format?

The browser may not support AVIF canvas encoding. When that happens, the output can fall back to another type and Format Guidance reports the mismatch.

Why did transparency disappear?

JPEG and BMP are opaque in this workflow, so transparent pixels are painted over the selected matte color. PNG, WebP, AVIF, and ICO can preserve alpha unless flattening is selected.

Can animated files be converted?

Animated GIF and animated WebP files can be used as sources, but the output is one still frame. Use an animation workflow when frame timing or multiple frames must be preserved.

Why is the converted file larger?

Changing format, dimensions, or compression can increase bytes. BMP is uncompressed, PNG can be large for photos, and converting HEIC to JPEG can grow the file even when compatibility improves.

Why was my image rejected?

The source may exceed the browser-side file limit, the output may exceed the canvas limit, the file may not be decodable in this browser, or the HEIC/HEIF decoder may not recognize the file.

Glossary:

Alpha: Transparency information in decoded pixels.
Codec: The compression method used to store image data inside a file format.
Container: The file structure that carries image data, labels, metadata, and sometimes multiple images or frames.
Lossless: Compression that preserves pixel values after decoding.
Lossy: Compression that reduces bytes by discarding some visual detail.
Matte: The solid background color painted behind transparent pixels when output cannot keep alpha.
Resampling: The interpolation step used when pixels are scaled to a new size.
HEIF brand: A short identifier in a HEIC or HEIF file header that signals the container variant.
ICO payload: One square icon image stored inside an ICO file.
Byte-size change: The percentage difference between source bytes and output bytes.

References:

Image file type and format guide, MDN Web Docs.
HTMLCanvasElement: toBlob() method, MDN Web Docs.
High Efficiency Image File Format, HEIC/HEIX brands, Library of Congress.
ICO Format Overview, Microsoft Learn.