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Bulk BMP to AVIF Converter

Convert uncompressed BMP images to AVIF, the most efficient web image format available, and reduce file sizes by 97% or more. A 6 MB BMP becomes an AVIF under 150 KB. Full color, full transparency, full browser support.

Convert
Drop your images here or click to browse. JPG, PNG, WebP, AVIF, HEIC, GIF, BMP and ZIP archives. Select images Up to 500 images · nothing is uploaded

Settings

Everything here is optional. The defaults work for most images.

Target file size

Processing

File names

Original image
Processed image
Converted Original
Browser-based processing Zero server uploads Works on any device

Convert BMP to AVIF in 3 Steps

No account, no install, no queue. Drop your BMP files in and the AVIF versions are ready to download.

  1. Step 1

    Drop your images in

    Drag files onto the page, click to browse, or drop in a ZIP and every supported image inside is pulled out. JPG, PNG, WebP, AVIF, HEIC, GIF and BMP all work, mixed together in the same batch.

  2. Step 2

    Adjust if you want to

    Choose your output format and drag the quality slider. That is the whole setup. Settings holds a KB target, resizing and batch renaming if you want them, and can stay closed if you do not.

  3. Step 3

    Download your AVIF files

    Conversion starts on its own, so there is usually nothing to press. Batches over 40 wait for one click so nothing runs away with your machine. Download files one at a time or take the whole batch as a single ZIP.

Why Convert BMP to AVIF?

BMP and AVIF sit at opposite extremes of the image format efficiency spectrum. BMP applies zero compression. A 1920×1080 image always weighs exactly 6 MB regardless of content. AVIF applies the most sophisticated compression algorithm in mainstream use, backed by the AV1 codec developed by an alliance of Google, Apple, Netflix, Mozilla, and Microsoft. The result: a 6 MB BMP becomes an AVIF under 150 KB at quality 80, with no meaningful visual difference. That's a 97%+ reduction in file size. And unlike JPEG, which is also dramatically smaller than BMP, AVIF retains full transparency support and delivers better visual quality per kilobyte. For BMP content heading to any modern web delivery context, AVIF is simply the most efficient destination format on earth.

BMP

Windows Bitmap Format

BMP is Windows' raw pixel storage format from the late 1980s. It stores every pixel at full bit depth with absolutely no compression, which means file size is always proportional to pixel count, regardless of image content. A solid-color 1920×1080 BMP weighs the same 6 MB as the most complex photograph at the same resolution. BMP was designed for Windows' internal display pipeline, not for sharing, delivery, or any use case that involves moving an image off the machine where it was created.

Zero compression. ~6 MB per full-HD image
File size independent of image content complexity
Windows-native. No web browser support
Designed for internal use, not sharing or delivery
AVIF

AV1 Image File Format

AVIF is the most compressed mainstream image format available today. Built on the AV1 codec by an open alliance of the world's largest technology companies, it achieves file sizes 97% smaller than BMP, 50% smaller than JPEG, and 20–30% smaller than WebP. All while maintaining excellent visual quality, full alpha transparency, and HDR support. Supported across Chrome, Firefox, Safari, and Edge, AVIF is the definitive endpoint for any BMP content heading to modern web delivery.

95–98% smaller than equivalent BMP files
Full alpha transparency + HDR support
Supported in Chrome, Firefox, Safari, Edge
Best quality-per-byte of any web image format

6 MB BMP. Under 150 KB AVIF.

BMP to AVIF is the single largest file size reduction available on this site. Zero compression becomes the world's best compression. In one batch, privately, with no installation.

True Bulk Conversion

Convert 10 or 500+ BMP files to AVIF in one batch. No file limits, though BMP files are very large by design, so large batches involve processing significant raw data volume. AVIF encoding is also compute-intensive, so allow extra time for large jobs.

100% Private & Secure

Client-side only. Your BMP files never leave your device. No server, no cloud, no third party sees your images at any point during conversion.

Adjustable Quality Control

Set AVIF quality from 1 to 100. Quality 70–85 is the optimal range. AVIF's AV1 codec retains visual quality far more efficiently at lower settings than any other format. Given the enormous headroom from BMP's 6 MB baseline, even quality 60 often produces excellent results.

ZIP Upload & Download

Upload a ZIP of BMP files. Download all converted AVIF images as a single ZIP. Essential for bulk legacy asset migrations destined for modern web delivery pipelines.

Batch File Renaming

Set a custom prefix, separator, numbering, and.avif extension. Preview the filename pattern before downloading. Essential when dealing with auto-generated BMP filenames from Windows applications.

the maximum size option

Need AVIF output under 100 KB for a strict CDN budget or upload limit? Set a target KB and the tool automatically adjusts quality per image. Starting from a 6 MB BMP baseline, there is extraordinary compression headroom to work with.

Works on Every Device

Windows, Mac, Linux, Chromebook, iPhone, Android. Any modern browser handles the conversion. Convert Windows BMP content to the most efficient web format without needing any Windows-specific software.

Selective Processing

Upload a batch of BMP files and select only the images you need as AVIF. Only those files are converted and downloaded. No pre-filtering of your library required before uploading.

Full Transparency Preserved

AVIF fully supports alpha transparency. Transparent areas in 32-bit BMP files carry through to the AVIF output perfectly. Standard 24-bit BMPs don't contain transparency. To flatten transparency to white instead, use our BMP to JPEG converter.

BMP vs AVIF vs JPEG

How does the oldest mainstream format compare to the newest? The gap is as large as it gets in practical image format comparisons.

Feature AVIF JPEG BMP
File size vs BMP baseline 95–98% smaller 93–97% smaller Baseline (0% compression)
Compression algorithm AV1 (state of the art) DCT (1992) None. Raw data
Transparency support Full alpha channel No (white fill) 32-bit BMP only
HDR & wide color gamut Yes No No
Browser support Chrome, Firefox, Safari, Edge Universal No browser support
Email client support Limited Universal Limited
Year introduced 2019 1992 1987
Best use case Modern web delivery Email, print, legacy Windows-internal only

When You Need BMP to AVIF

BMP to AVIF is the conversion for when Windows-native content needs to reach the modern web at maximum efficiency.

Maximum Web Performance from Legacy BMP Sources

If Windows-native tools are your source and a modern website is your destination, BMP to AVIF is the most direct path to maximum performance. A 6 MB BMP becoming a 150 KB AVIF means faster page loads, dramatically lower bandwidth consumption, and improved Core Web Vitals scores. All from a single batch conversion step.

CDN & Storage Cost Elimination

If you're migrating a BMP-heavy asset library to cloud storage or a CDN, converting to AVIF first reduces your total storage footprint by 97% or more. 100 BMP files at 600 MB becomes an AVIF collection under 10 MB. A reduction that compounds across storage costs, bandwidth charges, and transfer times at any scale.

Legacy Windows Application Web Migration

When migrating a Windows desktop application to a web or cloud platform, BMP assets from the original Windows environment need to be converted for web delivery. AVIF is the optimal target. The smallest possible files for modern browsers, with full quality preserved from the lossless BMP source.

Industrial & Medical Imaging Web Publication

Industrial software, medical imaging systems, and scientific applications on Windows frequently export BMP files. When that content needs to be published to a web portal, reporting dashboard, or online documentation system, AVIF gives you the smallest possible files that still render with full fidelity in every modern browser.

Building Multi-Format Delivery Pipelines from BMP

Best practice for modern web delivery is serving AVIF to supporting browsers with WebP and JPEG fallbacks for older clients. Convert your BMP library to AVIF here to generate the primary delivery format, then use our other BMP converters to build the complete fallback stack.

Game & Software Asset Web Delivery

Game engines and desktop software development tools that output BMP assets for UI, textures, and documentation need those assets converted for any web-facing delivery context. AVIF is the most efficient format for delivering that content through a browser-based store page, community site, or documentation portal.

Trusted for BMP to AVIF Conversion

Real feedback from people converting BMP to AVIF every week, from teams in the UK, US, India, Japan, Pakistan, the UAE and beyond.

4.7out of 5 · 12 reviews
  • Our client contracts forbid uploading unreleased assets to third-party servers, which rules out almost every online converter. This one runs in the browser, so the BMP files never leave the machine. I checked the network tab myself before I trusted it.

    Min-jun ParkFront-end engineer Seoul, South Korea · Aug 2026
  • Faster than uploading would have been. Because it runs on my machine there is no waiting for a server queue. The BMP files convert as fast as my laptop can process them.

    Hannah VogelOnline shop owner Hamburg, Germany · Jul 2026
  • The comparison slider is what earned my trust. Being able to drag across the actual image and check the AVIF output against the original BMP before downloading is not something the other free tools bother with.

    Sana TariqPublishing assistant Karachi, Pakistan · Jun 2026
  • Added some files mid-batch and the button changed to say it would only process the new ones. Little detail, but it means I am not reconverting work that is already done.

    Chloé MarchandArt director Lyon, France · Apr 2026
  • ZIP in, ZIP out. That is the whole workflow for me. It even skips the non-image files in the archive without complaining, which I did not expect.

    Priya RaghavanE-commerce manager Bengaluru, India · Mar 2026
  • Genuinely no ads, no watermark, no daily cap. I kept waiting for the catch and there isn't one. I have converted a few thousand BMP files at this point.

    Alex PetrovFull-stack developer Sofia, Bulgaria · Feb 2026
  • Used it on Windows at the office and on a Mac at home with identical results. No install, no licence, nothing to sync.

    Fatima Al-MansouriBrand manager Dubai, United Arab Emirates · Jan 2026
  • Been using a paid TinyPNG plan for years for this. Honestly, for straightforward BMP to AVIF work this is quicker. No launch time, no export dialog, just drop and go.

    Sofia RicciEditorial designer Milan, Italy · Dec 2025
  • Converted our whole media library and Lighthouse stopped complaining about image delivery. Largest Contentful Paint came down noticeably on the pages with the heaviest BMP assets.

    James WhitfieldFront-end developer Manchester, United Kingdom · Nov 2025
  • The batch handling is the reason I keep this bookmarked. 150 BMP images to AVIF in one pass, with a progress bar that actually tells you which file it is on. Most converters choke well before that.

    Vikram DesaiSaaS marketing Pune, India · Oct 2025
  • Coming from BMP, the thing you notice immediately is the size difference. AVIF gives me the best compression available today and my page weight dropped noticeably after the swap.

    Kwame AsanteCreative director Manchester, United Kingdom · Sep 2025
  • I work with pre-release marketing images and cannot put them on someone else's server. Everything here happens locally, so BMP to AVIF conversion is finally something I can do without a compliance conversation first.

    Jonas WeberDevOps engineer Munich, Germany · Aug 2025

BMP to AVIF Conversion and Compression Explained

What changes when you convert BMP to AVIF, what it costs, and how to pick a quality setting you will not regret.

A BMP stores raw pixel data with no compression worth the name, which is why a 4000 pixel scan can run past 45 MB. Nothing about that helps you. Converting to AVIF keeps the image and discards the waste, usually cutting the file to a tenth of its original size with no change you can see at normal viewing distance.

Both formats are lossy, so the conversion re-encodes rather than copies. Keep quality at 85 or above if the file is going to be edited again, and use the before and after slider to check the first image of a batch before you commit to the rest.

Set quality once and it applies to the whole batch, so a folder of two hundred files takes the same number of decisions as one. AVIF encoding is genuinely slower than the alternatives, so a large batch takes minutes rather than seconds. It runs on your own processor, which is why it is not instant, and also why nothing is queued behind other people's jobs. If you are working to a hard limit, such as a content management system that rejects anything over 200 KB, open Settings and set a maximum file size instead of a quality percentage. The encoder then searches for the best quality that fits your budget, file by file.

All Formats. One Tool.

BMP to AVIF is one of twenty-four conversion paths here, and each one has its own page with defaults already set for that pair. Whichever you land on, the tool behind it is the same: it accepts JPG, PNG, WebP, AVIF, HEIC, GIF and BMP, reads ZIP archives, and handles up to 500 images in a single batch.

Conversion runs in your browser using your own processor, so nothing is uploaded, nothing is queued behind other people, and there is no account, no watermark and no daily cap. Close the tab and the files are gone from memory; they were never anywhere else.

If you need a smaller file rather than a different format, the image compressor keeps your originals and works to a quality level or a size in kilobytes. To change dimensions, the image resizer handles fit, fill and crop, or stretch across a whole folder at once.

Frequently Asked Questions

Quick answers about converting BMP to AVIF.

Is it safe to convert BMP to AVIF on SmallerImages?
Yes. Everything runs entirely in your browser. No files are uploaded to any server at any point. Your images stay on your device throughout the conversion process.
How much smaller will AVIF files be compared to my BMP files?
Typically 95–98% smaller. The largest size reduction of any conversion on this site. A 6 MB full-HD BMP becomes an AVIF under 150 KB at quality 80. Because BMP applies zero compression, AVIF's AV1 codec has the maximum possible headroom to work with, resulting in extraordinary size reductions that are impossible starting from already-compressed source formats.
Will I lose quality converting from BMP to AVIF?
At quality 70–85, the AVIF output is visually indistinguishable from the BMP source for virtually all photographic and illustrated content under normal viewing conditions. AVIF is a lossy format at these settings, so there is technically some information loss, but the AV1 codec's quality retention at low settings is exceptional. Use the before/after slider to compare before batch-processing your full library.
What quality setting should I use for AVIF?
Quality 70–85 is the optimal range for BMP-sourced AVIF. The AV1 codec retains visual quality far more efficiently at lower numbers than JPEG or WebP. Quality 75 in AVIF looks comparable to JPEG quality 90 at a fraction of the file size. Since BMP is your lossless source, you have full flexibility across the quality range with no pre-existing compression artifacts to worry about.
Does AVIF preserve BMP transparency?
Yes. AVIF supports full alpha channel transparency. Transparent areas in 32-bit BMP files are preserved exactly in the AVIF output. Standard 24-bit BMP files don't contain transparency data. If you need to flatten transparency to a white background, use our BMP to JPEG converter instead.
Which browsers support AVIF?
Chrome (85+), Firefox (93+), Safari (16+), and Edge (121+) all support AVIF natively. Covering over 90% of global web users as of 2024. For browsers that don't support AVIF, serve WebP or JPEG fallbacks using the HTML picture element.
Why choose AVIF over WebP for BMP conversion?
AVIF gives you 20–30% smaller files than WebP at equivalent visual quality, making it the most efficient choice for web delivery. Since BMP is your uncompressed source, you lose nothing by using AVIF. The full quality of the original BMP is available for the AVIF encoder to work with. Use our BMP to WebP converter if you need slightly broader tool compatibility or faster encoding times.
How many BMP files can I convert at once?
No limit. Keep in mind that BMP files are very large and AVIF encoding is compute-intensive. This is the most resource-heavy combination on the site. A batch of 100 full-HD BMPs involves processing around 600 MB of raw data and performing intensive AVIF encoding on each. A progress bar tracks large jobs as they run.
Is SmallerImages completely free?
Yes. No premium plans, no watermarks, no file limits, no account required, and no ads.
Can I upload a ZIP of BMP files?
Yes. Upload a.zip archive and all BMP images inside are extracted and queued automatically. Download all converted AVIF files as a new ZIP in one click when done.

Zero Compression to the Best Compression. In One Step.

BMP stores raw pixels with no compression whatsoever. AVIF applies the most sophisticated image compression algorithm in mainstream use today. The gap is 97% smaller files, full color fidelity, smooth transparency, and support across every modern browser. Convert your BMP library to AVIF for free, privately, without uploading a single file.

Convert BMP to AVIF Now