🖼️ Image Converter

Convert BMP to AVIF — From the Worst File Size to the Best

BMP is the most storage-inefficient image format — zero compression, every pixel raw. AVIF is among the most efficient — 50% smaller than JPEG at equivalent quality. Convert directly and go from a 6MB BMP to ~150KB AVIF in one step. No upload, no account, 100% private.

⚡ Convert BMP to AVIF Now Browse All Tools

✓ Free forever ✓ No upload ✓ No signup ✓ Batch convert

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Got bloated BMP files taking up storage?

Drop your BMPs — convert to AVIF and shrink by 95%+ in seconds, no upload needed

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From Worst to Best Compression: BMP to AVIF

BMP (Bitmap) is a format from 1988 that stores images as raw, uncompressed pixel data. A 1920×1080 screenshot saved as BMP is roughly 6MB of raw data — every single pixel encoded at 3 bytes minimum. There is no compression, no optimization, no algorithm making it smaller. BMP exists as a lowest-common-denominator format that every Windows application can read.

AVIF (AV1 Image File Format) is the opposite extreme. Derived from the AV1 video codec, it uses HEVC-class compression algorithms to achieve file sizes 50% smaller than JPEG and 20–30% smaller than WebP at identical visual quality. Converting BMP to AVIF in a single step eliminates decades of format inefficiency and produces web-optimized images that Chrome 85+, Firefox 93+, and Safari 16+ all render natively.

📉 95%+ file size reduction — a 6MB BMP becomes ~150KB as AVIF
🏆 Better than JPEG at same visual quality — AVIF wins every quality-per-byte comparison
🎨 Full alpha channel support — transparency preserved in AVIF output
🌐 Chrome 85+, Firefox 93+, Safari 16+ all render AVIF natively
📊 Core Web Vitals improvement — dramatically smaller images improve LCP scores
🔒 100% private — files never leave your device during conversion

How to Convert BMP to AVIF

Open the Converter

Click "Convert Now" — the image tab with BMP → AVIF will be pre-selected.

Add Your BMP Files

Drag and drop your .bmp files or click to browse. Enable Batch mode for multiple files at once.

Set Quality Level

Quality 80–90 gives visually lossless results at tiny file sizes. Higher quality = slightly larger AVIF.

Download Your AVIFs

Converted files download immediately — web-ready, 95% lighter than the originals.

Why BMP Files Are So Large

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Raw Pixel Storage

BMP stores every pixel at 3–4 bytes. A 1920×1080 image = ~6.2 million bytes minimum. Zero compression applied.

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1988 Format

BMP predates modern compression algorithms. It was designed for simplicity, not efficiency — those tradeoffs still apply today.

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Storage Hog

A folder of 100 screenshots saved as BMP can hit 500MB+. The same images as AVIF fit in under 25MB.

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Web Incompatible

Browsers can technically display BMP but the load time is terrible. No web developer intentionally serves BMP files.

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AVIF Solves All of This

Modern HEVC-derived algorithms compress the same visual information into 5% of the space with imperceptible quality loss.

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100% Private

Canvas API in your browser handles conversion. Your files never touch a server.

Frequently Asked Questions

A 1920×1080 BMP screenshot (~6MB) typically becomes 100–300KB as AVIF — a 95–98% reduction. AVIF's HEVC-derived compression is vastly more efficient than BMP's uncompressed raw pixels. BMP stores every pixel as 3–4 bytes of raw data; AVIF uses advanced predictive coding and transforms to represent the same image information in a fraction of the space.

AVIF supports both. Lossy AVIF (default) gives the best size reduction. Lossless AVIF is larger but pixel-perfect. For most web use, lossy AVIF at quality 80–90 is indistinguishable from the original. Since BMP is already uncompressed, lossy AVIF at high quality retains all visually important detail with dramatic file size savings.

Yes. AVIF supports full alpha channel transparency. BMP's standard 24-bit format doesn't have transparency; 32-bit BMP does include an alpha channel. If you need transparent output, AVIF and PNG are both solid options — AVIF will be significantly smaller than PNG for the same transparency.

Safari 16+ (released 2022) supports AVIF. iOS 16+ also supports AVIF. For older Safari or iOS users, use the <picture> element with WebP or JPEG as a fallback source — modern browsers will pick AVIF automatically when supported, falling back gracefully otherwise.

AVIF is 20–30% more efficient than WebP at the same quality. Both are far superior to BMP. Choose AVIF for cutting-edge web performance where you want maximum compression; choose WebP for broader compatibility (Safari 14+ vs 16+). Both are dramatically better than leaving images as BMP — even WebP reduces a 6MB BMP to under 500KB.

Photoshop 23.4+ (released 2022) added native AVIF support. Older versions require the fnordware AVIF plugin. For broad editing compatibility, keep a PNG or JPEG copy alongside AVIF files — AVIF is the delivery format for the web, while PNG or TIFF are better suited for editing workflows where you need round-trip fidelity.

Yes — 100% free, no signup, no upload. The Canvas API in your browser converts BMP to AVIF entirely on your device. Your files never leave your computer, and there are no limits, no watermarks, and no account required.