How to Convert Image Formats Online
Converting an image from one format to another used to require desktop software like Photoshop or GIMP. With Pixab AI's browser-based converter, the entire process takes under a minute — no software to install, no account to create, and no files sent to any server. Here is exactly what happens at each step.
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Upload Your Images
Drag one or more image files directly onto the upload zone, or click anywhere inside it to open your device's file picker. The converter accepts the most widely used formats: JPG, JPEG, PNG, WebP, AVIF, GIF, BMP, HEIC, and HEIF. The HEIC and HEIF formats are particularly common on iPhones, where they are the default photo format — our converter handles them without any special setup. On mobile, tapping the upload area opens your photo gallery directly. There is no per-file size limit enforced by the converter itself; the practical limit is determined by your device's available RAM.
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Choose Your Target Format
Select the format you want your images converted to from the format selector. The four output options are JPG, PNG, WebP, and AVIF. JPG is the safest choice for maximum compatibility — it is supported by every device, operating system, and application without exception. PNG is the right choice when your image has a transparent background or contains text and graphics with sharp edges. WebP is the recommended format for any image displayed in a web browser — smaller than JPG at the same visual quality, and supported by all modern browsers. AVIF goes even further in compression but requires a newer browser. After converting, you may want to compress the converted image further to squeeze out additional file size savings.
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Adjust Quality for Lossy Formats
For JPG, WebP, and AVIF output formats, a quality slider lets you control the trade-off between visual fidelity and file size. Quality 85% is an excellent default for most photographs — the output is visually indistinguishable from the original at normal viewing distances while being substantially smaller. For images destined for web publishing where load speed matters, 75–80% is a common target. For archival or printing purposes, 90–95% is more appropriate. PNG output is always lossless, so the quality slider does not apply — the file size is determined entirely by image content rather than a quality setting. If the primary goal is reducing file size after converting, our image compressor gives you fine-grained control after conversion.
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Click Convert and Watch It Process
Click the Convert button to begin processing. Each image is handled individually inside your browser tab — the conversion happens on your device's CPU, not on a remote server. For standard JPG, PNG, and WebP conversions, processing typically completes in under a second per image using the browser's built-in Canvas API. HEIC decoding and AVIF encoding involve additional WebAssembly steps and may take two to five seconds per image depending on resolution and device speed. You will see a progress indicator for each file as it completes. If you also need to adjust the dimensions — for example, to match specific social media sizes — the image resizer works as a natural next step after conversion.
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Download Your Converted Files
Once conversion is complete, each file shows its original format, new format, original size, and converted size. Download files individually with a single click, or collect all of them in one ZIP archive using the "Download All" button. The before-and-after size comparison lets you verify the results at a glance. If you need to combine your converted images into a single document — for instance, to submit a multi-page application or create a photo album — our Image to PDF converter bundles them into a single compact PDF in one step.
Why Use Pixab AI's Format Converter?
Complete Privacy — Your Images Never Touch a Server
The majority of online image converters work by uploading your file to a remote server, processing it there, and returning the result as a download. That means your image — potentially containing personal photos, scanned documents, or confidential business materials — travels across the internet and sits temporarily on hardware you have no control over. Pixab AI processes everything inside your browser tab using JavaScript and WebAssembly. There is no upload step, no transmission, and no server involvement at any point. Your images stay on your device from start to finish. For professionals handling sensitive imagery such as legal documents, medical records, or unreleased product photos, this distinction is not just a feature — it is a requirement.
Native HEIC Support — Convert iPhone Photos Without Extra Apps
Since iOS 11, Apple has used HEIC as the default camera format on iPhones and iPads. HEIC files are roughly half the size of equivalent JPEGs at the same quality, which is great for iPhone storage — but most non-Apple applications and many online platforms still cannot open them natively. Windows Photo Viewer, most social media platforms, and email clients on Android all struggle with HEIC. Rather than installing a dedicated HEIC converter app or changing your iPhone camera settings to a lower-quality format, simply drop your HEIC files into our converter and get universally compatible JPG, PNG, or WebP output instantly. The conversion uses the heic2any library, which runs entirely in the browser — no plugin required. After converting, if you also need to remove a cluttered background from a portrait or product photo, our background remover handles PNG output natively.
Modern Format Support — WebP and AVIF for the Web
JPEG was standardised in 1992 and PNG in 1996. Both are still widely used and fully valid, but newer formats achieve dramatically better compression. WebP, developed by Google, produces files 25–35% smaller than JPEG at the same visual quality and also supports transparency like PNG. AVIF, based on the AV1 video codec, achieves 40–60% smaller files than JPEG. Both formats are now supported by all major browsers, making them the clear choice for any image displayed online. After converting to WebP or AVIF, you can run the result through our image compressor to push file sizes even lower — particularly useful when targeting Google PageSpeed Insights recommendations or specific file size budgets.
Completely Free — No Account, No Watermarks, No Monthly Limits
Many conversion tools offer a "free tier" that is free in name only: conversions are capped at five or ten files per day, file sizes are limited to a few megabytes, output images carry watermarks, or key formats like AVIF are locked behind a paid plan. Pixab AI has none of these restrictions. The converter is genuinely free with no daily quota, no per-file limit, no watermarks on outputs, and no account required at any stage. We are supported by non-intrusive advertising rather than paywalls, so every format and every feature is available to everyone, all the time. For related document workflows like converting images to PDF for submission or archiving, our Image to PDF tool is equally free and unlimited.
Batch Conversion — Handle Dozens of Files at Once
Converting files one at a time is frustrating when you have a folder of product photos, a set of screenshots, or a batch of HEIC photos from your camera roll. Pixab AI lets you upload and convert multiple images simultaneously in a single session. All files are processed in parallel inside your browser and can be downloaded as a ZIP archive when done. For photographers, e-commerce managers, and web developers dealing with large image batches, this saves the tedium of running conversions one by one. You can also resize images in bulk using our dedicated resizer — useful for preparing images to exact pixel dimensions for social media, email headers, or CMS uploads before or after converting formats.
Works Everywhere — Any Browser, Any Device
There is nothing to download or install. The format converter runs in your browser, which means it works identically on Windows, macOS, Linux, Chromebooks, Android tablets, and iPhones. It has been tested on Chrome, Firefox, Safari, and Edge. The mobile interface is touch-optimised with large tap targets and smooth scroll behaviour. Whether you are sitting at a workstation converting a batch of product images for a website or standing at a market quickly converting a photo from your phone, the experience is consistent. For tasks that extend beyond format conversion — such as extracting images from a PDF document before converting them — our PDF to image converter handles that as a natural upstream step.
Common Use Cases for Image Format Conversion
Converting iPhone HEIC Photos for Sharing and Uploading
This is the single most common reason people search for an image converter. When you AirDrop or cable-transfer iPhone photos to a Windows PC, or try to upload them to a platform that does not support HEIC — which includes most social media sites, government portals, and older CMS platforms — you get an error or a blank preview. The fix is straightforward: drop your HEIC files into our converter, select JPG as the output format at 85% quality, and download universally compatible versions in seconds. The converted JPGs are indistinguishable from the originals at normal screen sizes and can be opened on any device, emailed, or uploaded anywhere without issues. If you want to remove the background from a portrait after converting it — a common step for professional headshots — our background remover works directly with the converted PNG or JPG output.
Optimising Images for Websites and Page Speed
Google's PageSpeed Insights and Core Web Vitals guidelines explicitly recommend serving images in next-generation formats — WebP or AVIF — rather than JPEG or PNG where possible. Converting your existing JPG or PNG image library to WebP can reduce total image payload by 30–40%, directly improving Largest Contentful Paint (LCP) scores and search rankings. After conversion, run the WebP files through our image compressor to reduce file sizes even further. The combination of format conversion and targeted compression is the most effective strategy for meeting Google's image performance requirements without degrading visible quality. If you also need to resize images to the correct display dimensions for your layout — removing unnecessary pixels before the format conversion — use our resizer as the first step in the pipeline.
Preparing Product Photos with Transparent Backgrounds
E-commerce product photography workflows often require images on a pure white or transparent background. The most common scenario is: a product photo arrives as a JPEG (no transparency support), the background is removed by our AI background remover, and the result needs to be saved as PNG to preserve the transparent cutout. Our converter handles the initial format step — if you receive product images as HEIC, AVIF, or BMP, convert them to JPG or PNG first. Once you have the product cutout as a PNG, it can be uploaded to Shopify, WooCommerce, Amazon, or any other platform without a distracting background competing with the product. For product catalogues that need to be packaged as a single document, our Image to PDF converter can assemble the full set into a presentation-ready PDF.
Converting PDF Page Screenshots and Scans to Usable Images
A common workflow in document processing is extracting pages from a PDF as images — for example, to include a single page of a report in a presentation, to share a specific page via messaging, or to use a diagram from a PDF in a different document. Our PDF to image converter extracts PDF pages as high-quality JPG or PNG files at your chosen DPI. Once extracted, our format converter can then convert those images to WebP for web publishing or AVIF for maximum compression — completing a full PDF-to-web-image pipeline without any server uploads. This is particularly useful for legal firms, publishers, and educators who regularly need to distribute individual pages from larger PDF documents.
Meeting File Format Requirements on Portals and Forms
Government portals, university admissions systems, visa applications, and professional certification platforms often specify a mandatory image format — almost always JPG. If your photo is stored as HEIC, PNG, WebP, or AVIF, the upload will be rejected or fail to preview correctly. Our converter resolves this instantly: upload your image in any supported format, select JPG as the output, and download a portal-compatible version. If the portal also has a strict file size limit — commonly 100 KB, 200 KB, or 500 KB per image — run the converted JPG through our image compressor at 60–70% quality to hit the target. If the form requires a specific image size like a passport-format photo, our image resizer has presets for common passport and ID photo dimensions.
Archiving and Long-Term Storage
When building a long-term image archive — family photos, business records, real estate portfolios — choosing the right format matters for future compatibility. PNG is the most conservative choice for archiving: it is lossless, widely supported, and not tied to any proprietary codec. JPEG is also a safe archival format, though lossy. Newer formats like AVIF and WebP, while excellent for current use, may face codec availability questions decades from now. For photographs you plan to archive indefinitely, converting to high-quality JPEG or PNG is the more prudent approach. Once you have your archive organised, our Image to PDF tool lets you bundle sets of images into a single PDF document for easier long-term storage and sharing.
How Format Converter Works
Understanding the technology behind format conversion helps you make better decisions about which format to choose and what quality settings to use. Here is a plain-language explanation of what happens under the hood.
The Canvas API: How Most Conversions Work
For converting to JPG, PNG, and WebP, the tool uses the browser's native Canvas API. The process works in three steps: first, the source image is decoded into an in-memory pixel buffer (an ImageData array of raw RGBA values). Second, this pixel data is drawn onto an HTML Canvas element. Third, the Canvas's toBlob() method re-encodes the canvas contents as a file in the target format, applying the quality setting you specified. This is the same encoding mechanism used by your browser to prepare images for web display — it is rigorously tested, continuously optimised by browser vendors, and produces output identical to what professional tools would generate at the same quality level.
HEIC Decoding: The heic2any Library
HEIC files use the High Efficiency Image Container format, which wraps images encoded with the HEVC (H.265) video codec. Most browsers cannot natively decode HEIC because HEVC involves patent licensing. Our converter uses the open-source heic2any library, which ships a pure-JavaScript HEVC decoder as a WebAssembly module. When you upload a HEIC file, the library decodes the HEVC-compressed image data into raw pixel values in your browser's memory, and then the Canvas API encodes it to your chosen output format. This entire pipeline runs locally on your device — no HEVC licence servers, no cloud processing, no network traffic.
AVIF Encoding: WebAssembly and the AV1 Codec
AVIF uses the AV1 codec for image compression. The browser's native Canvas API supports AVIF decoding in modern Chrome, Firefox, and Safari, but AVIF encoding (writing an AVIF file) is not uniformly available via toBlob() across all browsers. Our converter uses the @jsquash/avif WebAssembly library, which compiles the reference AV1 encoder to WebAssembly so it runs in any browser regardless of native codec support. This means you can encode AVIF output on Firefox or Safari even though those browsers' own Canvas implementation does not yet support AVIF encoding natively. The trade-off is that WebAssembly-based AVIF encoding is slower than native Canvas encoding — expect a few extra seconds for large images.
Lossy vs. Lossless Formats: What the Quality Slider Controls
Image formats fall into two fundamental categories. Lossless formats (PNG) preserve every pixel value exactly — the output is a mathematically identical reproduction of the input. Lossy formats (JPG, WebP, AVIF) discard some image data to achieve smaller files. The quality slider controls how aggressively data is discarded. For JPEG, the encoder divides the image into 8×8 pixel blocks, applies the Discrete Cosine Transform, and quantises the result — higher quality settings preserve more high-frequency detail (fine textures, sharp edges); lower settings introduce the characteristic blocky compression artifacts visible in heavily compressed JPEGs. WebP's algorithm uses larger, more flexible block sizes and more sophisticated prediction between blocks, which is why it achieves smaller files at the same perceptual quality. AVIF, derived from a video codec designed for high-compression efficiency, applies even more advanced inter-block prediction and entropy coding techniques.
Why Browser-Based Processing Preserves Privacy
In a server-based converter, your image travels from your device to a web server over HTTPS, is decoded and re-encoded on the server's hardware, is temporarily written to server disk or memory, and is then transmitted back to you as a download. Even with HTTPS encryption in transit, the file exists unencrypted on the server's memory and potentially in temporary disk storage during processing. Browser-based processing eliminates this entire chain. The image never leaves your RAM — it is decoded, re-encoded, and presented for download all within your browser tab. If you close the tab, every trace of the image is gone. This architecture makes our converter suitable for images you would never want to transmit over a network: medical imagery, legal documents, unpublished creative work, and personal photographs. After converting images that will become part of a PDF document, our PDF to image converter follows the same privacy-first approach.
Tips for Best Results
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Convert to WebP for Web Images
If your image will be displayed in a browser, WebP is almost always the best output choice. It is 25–35% smaller than an equivalent JPEG and supported by all modern browsers — Chrome, Firefox, Safari 14+, and Edge. After converting, use our image compressor to push file sizes even lower without perceptible quality loss.
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Use PNG Only When Transparency Is Needed
PNG's lossless compression makes it ideal for logos, icons, and images with transparent areas. For photographs, PNG produces unnecessarily large files — WebP or JPEG will give you 60–80% smaller outputs with no perceptible quality difference. If you need to remove the background from a photo to create a transparent PNG cutout, run our background remover on the image first, then save the result as PNG.
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Start with the Original, Not an Already-Compressed File
Every time you convert between lossy formats (JPEG to WebP, for example), the compression algorithm runs again and discards additional image data. If you convert a JPEG to WebP and then back to JPEG, you have applied two rounds of lossy compression — and the accumulated quality loss becomes visible. Always start from the best quality source available: the original RAW or high-quality JPEG from your camera. If the only version you have is a compressed JPEG, use a quality setting of 90–95% for the conversion to minimise additional quality loss.
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Resize Before Converting for Large Source Files
If your source image is 5000 px wide but only needs to display at 800 px, you are converting and storing four times more pixels than necessary. Reducing dimensions before converting reduces the raw data the encoder has to work with, resulting in a faster conversion and a smaller output file. Use our image resizer to set the correct dimensions first — it supports aspect-ratio locking and social media presets — then convert the appropriately sized image.
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Check AVIF Browser Support Before Deploying
AVIF delivers the smallest file sizes of any widely available format, but it requires a relatively recent browser: Chrome 85+, Firefox 93+, and Safari 16+. If your audience includes users on older operating systems or enterprise environments with locked-down browser versions, WebP is the more cautious choice. When in doubt, convert to WebP as the primary format — it offers a substantial size advantage over JPEG with near-universal browser support.
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Bundle Converted Images into PDF for Document Workflows
After converting a set of images — for example, converting a batch of HEIC scans to JPG or PNG — you may need to deliver them as a single document rather than individual files. Our Image to PDF converter takes your converted images and bundles them into a compact, properly ordered PDF with full control over page size, orientation, and margins. This is particularly useful for invoice scans, legal submissions, and photo portfolios.
Format Converter vs Alternatives
Several online image converters exist, each with different trade-offs. Here is an honest comparison of Pixab AI against the most commonly used alternatives — without overstating our strengths or unfairly dismissing competitors.
Pixab AI vs. CloudConvert
CloudConvert is a professional-grade conversion service that supports an enormous range of file types well beyond images — including audio, video, documents, and CAD files. Its breadth is genuinely impressive. However, CloudConvert requires an account for most usage, uploads all files to its cloud servers for processing, and operates on a credit-based pricing model — the free tier is limited to 25 conversion minutes per day, and high-volume use quickly requires a paid subscription. Pixab AI covers the most common image conversion scenarios entirely in your browser with no account, no upload, no credits, and no daily limit. For simple image format conversion tasks, there is no reason to involve a cloud service. If your image conversion workflow extends to PDF documents — extracting images from PDFs before converting formats — our PDF to image converter is part of the same free, private suite.
Pixab AI vs. Convertio
Convertio is one of the most widely used online conversion tools, supporting hundreds of file format pairs across images, documents, audio, and video. It is genuinely useful for obscure format conversions that few other tools support. For image conversion specifically, however, Convertio uploads your files to its servers — your images leave your device — and the free plan caps you at 100 MB per file and 10 conversions per day, with a queue for processing during peak hours. Pixab AI processes images locally without any upload, with no per-day conversion cap, and no queue. For the most common image conversion tasks (HEIC to JPG, PNG to WebP, JPG to AVIF), browser-based processing is faster and more private than routing files through a third-party cloud service. After converting, you can further compress your images to reach target file sizes — again, entirely in your browser.
Pixab AI vs. Online-Convert
Online-Convert has been around for many years and offers a wide range of conversion options across formats. The free tier is heavily limited: conversions are slower due to lower processing priority, and the site shows aggressive advertising during the conversion wait time. Files are uploaded to Online-Convert's servers for processing. Pixab AI converts images instantly in your browser with no queue, no wait time governed by server load, and no files leaving your device. The experience is notably faster for the typical image conversion task, and the absence of server-side processing means no privacy exposure. For users who also need to resize images or remove image backgrounds in the same session, Pixab AI provides these as integrated tools rather than requiring navigation to separate services.