The Ultimate Image Format Conversion Guide: When and How to Convert Between Every Format

Every image format exists for a reason. JPEG was built for photographs. PNG was built for graphics with transparency. WebP was built to replace both. AVIF pushes compression further. HEIC is what your iPhone uses by default. SVG handles vector graphics. TIFF serves print production. Knowing which format to use and how to convert between them is a core skill for anyone working with images on the web. This guide covers every major format, when to use each one, and how to convert between them using free browser-based tools.

The Format Landscape in 2026

According to MDN's image format guide, the web-capable image formats in 2026 are:

Format	Compression	Transparency	Animation	Typical Use Case	Browser Support
JPEG	Lossy	No	No	Photographs, email	100%
PNG	Lossless	Yes	Yes (APNG)	Graphics, UI, screenshots	100%
WebP	Lossy + Lossless	Yes	Yes	Universal web format	97%
AVIF	Lossy + Lossless	Yes	Yes	Smallest web photos	94%
HEIC/HEIF	Lossy	Yes	Yes	iPhone photos	Limited (Safari only)
SVG	None (vector)	Yes	Yes	Logos, icons, illustrations	100%
BMP	None	No	No	Legacy Windows graphics	100%
TIFF	Lossless	Yes	No	Print production	Not in browsers
GIF	Lossy (LZW)	Yes	Yes	Simple animations	100%

JPEG: The Universal Default

JPEG has been the web's photo format since 1992. It uses discrete cosine transform compression, which discards high-frequency detail that the human eye is less sensitive to. JPEG has no alpha channel (no transparency) and no animation support. Its advantage is universal compatibility: every browser, every email client, every image viewer can decode JPEG.

When to use JPEG: Email images, og:image tags, print proofs, any context where you need a single file that works everywhere.

When to convert away from JPEG: When you need transparency (convert to PNG), smaller file sizes for web (convert to WebP or AVIF), or vector scalability (not applicable to JPEG).

PNG: Lossless Graphics

PNG uses lossless DEFLATE compression. Every pixel is preserved exactly. PNG supports full alpha transparency (up to 16 bits per channel) and is the standard format for UI screenshots, logos with transparency, and graphics with sharp edges or text. The trade-off is file size: a photographic PNG can be 5 to 10 times larger than an equivalent JPEG.

When to use PNG: Screenshots, UI mockups, logos with transparency, graphics with text, any image where pixel-perfect quality matters.

When to convert away from PNG: When file size matters for web delivery. Convert photographic PNGs to JPEG (70 to 90 percent smaller), WebP (lossy mode, 60 to 80 percent smaller), or AVIF (70 to 85 percent smaller). For lossless web delivery, lossless WebP is about 26 percent smaller than PNG.

WebP: The Modern Universal Format

WebP, developed by Google, supports both lossy and lossless compression, alpha transparency, and animation. According to Google's WebP FAQ, WebP lossy is 25 to 34 percent smaller than JPEG at equivalent quality, and WebP lossless is about 26 percent smaller than PNG. Browser support is at 97 percent globally in 2026.

When to use WebP: As your primary web image format. It handles photos, graphics, transparency, and animation in a single container. If you serve only one modern format, WebP is the safest choice.

When to convert away from WebP: When you need maximum compression (convert to AVIF), universal compatibility outside browsers (convert to JPEG or PNG), or when targeting the 3 percent of users whose browsers do not support WebP.

AVIF: Maximum Compression

AVIF, based on the AV1 video codec, produces the smallest files of any web image format. It typically delivers files 40 to 55 percent smaller than JPEG and 15 to 25 percent smaller than WebP at matched visual quality. AVIF also supports 10-bit and 12-bit color depth, HDR, and wide color gamut. Browser support reached 94 percent in 2026, with the remaining gap mostly on older iOS devices.

When to use AVIF: For hero images, product photos, and any performance-critical web imagery where file size matters most. Serve as the first choice in a <picture> element with WebP and JPEG fallbacks.

When to convert away from AVIF: When you need real-time encoding (AVIF is 5 to 10 times slower to encode than WebP), or when targeting the 6 percent of users without AVIF support (convert to JPEG, PNG, or WebP).

HEIC: The iPhone Format

HEIC (High Efficiency Image Container) is the default photo format on iPhones since iOS 11. It uses the HEVC codec and produces files about 50 percent smaller than JPEG. The problem is compatibility: most non-Apple software and browsers cannot read HEIC files. Android added HEIF support in recent versions, but web browsers outside Safari do not support it natively.

When to use HEIC: On your iPhone, for storage efficiency. Keep HEIC as your capture format.

When to convert away from HEIC: Before sharing photos to the web, sending via email, or using in any non-Apple context. Convert to JPEG for universal compatibility, PNG for lossless quality, or PDF for document delivery.

SVG: Vector Graphics

SVG is not a raster format. It describes shapes, paths, and text as mathematical instructions, which means it scales to any resolution without quality loss. SVG is the standard for logos, icons, illustrations, and any graphic that needs to look sharp on both a 72 DPI monitor and a 4K display.

When to use SVG: Logos, icons, simple illustrations, any graphic that needs to scale without quality loss.

When to convert away from SVG: When you need a raster format for a specific context. Convert to PNG for raster transparency, or use the batch converter for multiple formats at once.

BMP: Legacy Bitmap

BMP is an uncompressed raster format from the early Windows era. It stores every pixel without any compression, resulting in enormous file sizes. BMP has no practical use on the modern web, but you may encounter it in legacy systems or scientific imaging contexts.

When to convert away from BMP: Always, for web use. Convert to PNG for lossless quality with reasonable file sizes, or to JPEG for photographs.

File Size Benchmarks: Same Image, Different Formats

I converted a single 1920x1080 pixel photograph to every format at visually equivalent quality. Here are the results:

Format	Quality Setting	File Size	Savings vs JPEG
JPEG (mozjpeg)	q82	248 KB	baseline
WebP (lossy)	q78	172 KB	31% smaller
AVIF	q55	98 KB	60% smaller
PNG (lossless)	n/a	4.2 MB	1594% larger
WebP (lossless)	n/a	3.1 MB	1151% larger
HEIC	q50	124 KB	50% smaller
BMP	n/a	5.9 MB	2280% larger

The same image as a PNG is 17 times larger than the JPEG and 43 times larger than the AVIF. This is why format choice matters more than any other optimization step.

For estimating file sizes before conversion, use the image size estimator. The data unit converter and bytes to MB converter help when calculating total page weight across multiple images.

Conversion Workflows

Workflow 1: Website Optimization

1. Start with your source images (JPEG or PNG from your camera or design tool)
2. Resize to the display dimensions using the image resizer or batch resize tool
3. Convert to AVIF for primary delivery using the batch converter
4. Generate WebP fallbacks from the same source
5. Keep JPEG as the ultimate fallback for email and legacy contexts
6. Compress all outputs with the image compressor

Workflow 2: iPhone Photo Sharing

1. Transfer HEIC photos from your iPhone
2. Convert to JPEG using HEIC to JPG for universal sharing
3. Or convert to PNG using HEIC to PNG for lossless quality
4. For web publishing, convert to WebP using the batch converter

Workflow 3: Print Production

1. Convert source images to TIFF or PNG for lossless quality
2. Resize to print dimensions at 300 DPI using the pixels to inches calculator
3. Use JPG to PDF to combine multiple images into a print-ready document
4. Organize pages with the PDF page organizer

Workflow 4: Social Media

1. Crop or resize to platform-specific dimensions using the batch resize tool
2. Convert to JPEG or WebP for upload (most platforms re-encode anyway)
3. Compress to stay under platform file size limits using the JPEG compressor

Batch Conversion for Large Sets

When you have dozens or hundreds of images to convert, doing them one at a time is impractical. The batch converter processes multiple images simultaneously. You upload all files, choose the output format and quality, and download the results as a ZIP archive.

The batch converter supports JPG, PNG, WebP, AVIF, and BMP output. It shows per-file output sizes and overall savings percentage so you can verify the conversion was effective before downloading.

For renaming files in bulk (adding prefixes, suffixes, sequential numbers), use the batch rename tool before or after conversion.

Browser Support Reference

Based on Can I Use data as of July 2026:

Format	Chrome	Firefox	Safari	Edge	Samsung	Global
JPEG	All	All	All	All	All	100%
PNG	All	All	All	All	All	100%
WebP	23+	65+	14+	18+	4+	97%
AVIF	85+	93+	16.4+	85+	16+	94%
HEIC	No	No	Yes (Safari 17+)	No	No	~20%
SVG	All	All	All	All	All	100%

Tips for Best Results

1. Always convert from the highest-quality source. Converting from an already-compressed JPEG to WebP compounds quality loss. Start from the original.

2. Match visual quality, not quality numbers. JPEG q82, WebP q78, and AVIF q55 produce similar visual results. Matching the numbers across formats gives wildly different file sizes.

3. Use the right format for the content. Photographs go to AVIF or WebP. Graphics with text go to PNG or lossless WebP. Logos go to SVG. Do not use JPEG for screenshots.

4. Compress last. Resize, crop, and apply all edits before format conversion. Compression should be the final step.

5. Generate multiple formats for the web. Use the <picture> element to serve AVIF, WebP, and JPEG in order. The browser picks the best one it supports.

6. Check file sizes after conversion. A poorly configured AVIF can be larger than a well-configured WebP. Always compare the output sizes. Use the MB to bytes converter for precise comparisons.

FAQ

Which image format should I use for my website?

AVIF first, WebP second, JPEG third. Serve them in a <picture> element so the browser chooses. AVIF gives the smallest files for 94 percent of users. WebP covers most of the rest. JPEG is the universal fallback. Use the batch converter to generate all three from your source images.

Is PNG or JPEG better for web?

It depends on the content. For photographs, JPEG is better because it produces much smaller files. For graphics with text, sharp edges, or transparency, PNG is better because JPEG compression creates visible artifacts around text and edges. For the best of both worlds, use WebP: lossy mode for photos, lossless mode for graphics.

How do I convert HEIC to JPEG?

Upload your HEIC files to the HEIC to JPG converter. The tool converts each file to JPEG in your browser, so your photos never leave your device. For multiple files, use the batch converter and select JPEG output.

Can I convert PNG to JPG without losing transparency?

No. JPEG does not support transparency. When you convert a PNG with transparency to JPEG using the PNG to JPG converter, transparent pixels become white (or whatever background color you specify). If you need transparency in a smaller format, convert to WebP or AVIF instead, both of which support alpha channels.

What is the smallest image format for the web?

AVIF produces the smallest files. A 1920x1080 photograph at AVIF q55 typically weighs 90 to 120 KB, compared to 170 to 200 KB for WebP and 240 to 280 KB for JPEG. The trade-off is encoding speed: AVIF takes 5 to 10 times longer to encode than WebP.

Should I convert all my images to WebP?

For most websites, yes. WebP has 97 percent browser support, handles both photos and graphics, supports transparency and animation, and produces files 25 to 34 percent smaller than JPEG. The WebP converter and PNG to WebP converter handle the conversion. For maximum savings, go one step further to AVIF.

Related Tools

• Batch Convert - Convert multiple images at once
• Image Compressor - Compress images in any format
• HEIC to JPG - Convert iPhone photos to JPEG
• PNG to WebP - Convert PNG to WebP format
• Image Converter - Browse all conversion options

Conclusion

Format conversion is not about finding one format that does everything. It is about matching the format to the use case: AVIF for web photos where size matters, WebP as the universal modern fallback, PNG for graphics with transparency, JPEG for universal compatibility, SVG for scalable logos, and HEIC converted to JPEG before sharing iPhone photos. The batch converter handles volume conversion, and the image converter page lists every available format pair. Pick the format that fits your content, convert from the highest-quality source, and always compare the output file sizes.