Best Online Image Converters: HEIC, AVIF, WebP, RAW
Why Image Format Conversion Is Still a Mess in 2026
If you shoot on an iPhone, your photos land in HEIC. If you work with a modern web stack, your designers are probably pushing AVIF or WebP. If you shoot professionally, you are dealing with Canon CR3, Nikon NEF, Sony ARW, or Fujifilm RAF files. And somewhere downstream, a client, a CMS, or a print shop still wants a plain JPEG or PNG. The result is a fragmented workflow that forces people to reach for conversion tools constantly. The problem is that not all online converters handle these formats equally. HEIC support, for example, requires licensing Apple's HEIF codec implementation — some tools quietly fail on HEIC files shot in HDR mode or with depth maps embedded. AVIF is computationally expensive to encode; a tool that advertises AVIF output but throttles CPU time on free tiers will produce slow, low-quality results. RAW support is the hardest bar to clear: there are over 200 distinct RAW variants across camera manufacturers, and most online tools support only a fraction. This article compares the most widely used online image converters — CocoConvert, Convertio, Cloudconvert, Squoosh, and ILoveIMG — across the formats that actually cause headaches. We will look at free tier limits, signup requirements, output quality controls, API access, and where each tool genuinely falls short. No tool wins on every dimension, and we will be specific about that.
HEIC Conversion: The iPhone Photo Problem
HEIC files from modern iPhones can contain HDR metadata, Live Photo motion data, depth information, and wide-gamut color profiles (Display P3). A converter that simply strips the HEIC container and dumps a flat JPEG is losing information you may care about. Cloudconvert handles HEIC exceptionally well. It preserves EXIF data reliably, respects the embedded ICC color profile, and lets you choose output color space explicitly — useful if you are preparing images for print (sRGB) versus screen (Display P3 passthrough). Their free tier gives you 25 conversion minutes per day, which translates to roughly 80–120 typical iPhone photos before you hit the wall. Cloudconvert does require account creation to access batch processing, and paid plans start at $9.99 for 500 conversion minutes. CocoConvert converts HEIC to JPEG, PNG, and WebP without requiring signup for single-file jobs. The free tier allows up to 30 files per day at up to 25 MB per file. It preserves EXIF metadata and handles standard HEIC files correctly. Where it falls short: Live Photo data (the embedded video component) is discarded, and HDR tone mapping is basic — you will not get the same highlight retention that Cloudconvert's libheif pipeline produces on HDR shots. If you are a photographer who shoots in HDR mode, Cloudconvert is the better pick for HEIC specifically. Convertio supports HEIC conversion but caps free users at 100 MB per file and 2 conversions simultaneously, which is fine for occasional use. Their output quality is adequate but metadata handling is inconsistent — GPS coordinates sometimes drop from the EXIF block on files over 15 MB, a bug that has been reported in user forums but not publicly acknowledged.
AVIF and WebP: Modern Formats for the Web
AVIF achieves roughly 50% smaller file sizes than JPEG at equivalent visual quality, and WebP sits about 25–30% smaller. For anyone managing a high-traffic image-heavy website, the difference is measurable in Core Web Vitals scores and bandwidth bills. Squoosh, Google's open-source converter, is the gold standard for AVIF and WebP output quality control. Running entirely in the browser via WebAssembly, it exposes the actual encoder settings: for AVIF you can set the CQ level (0–63, where lower is higher quality), the speed preset (0 = slowest/best, 10 = fastest), and chroma subsampling (4:4:4 or 4:2:0). For WebP you control the quality slider and the method parameter (0–6). This level of control is unmatched by any other free tool. The catch: Squoosh is single-file only. There is no batch processing, no API, and no cloud storage. If you need to convert 500 product images, Squoosh is not your tool. CocoConvert handles WebP output well, with a quality slider (1–100) and the option to output lossless WebP — useful for UI assets and logos where compression artifacts are unacceptable. AVIF output is available and produces competitive file sizes, though the encoder speed is set conservatively on the free tier, meaning a 20 MB source file can take 30–45 seconds to encode. Batch jobs of up to 30 files are supported without signup, which is a meaningful differentiator against Squoosh for small-to-medium batch work. ILoveIMG supports WebP conversion but does not offer AVIF output at all as of this writing — a significant gap for anyone building to modern web standards. Their interface is simple and fast for WebP, but the lack of quality controls (you get one quality preset) limits its usefulness for production workflows.
RAW Format Support: Where Most Tools Fail
RAW conversion is where the gap between tools becomes most obvious. The challenge is not just parsing the RAW container — it is applying demosaicing, white balance, and tone curve correctly for each camera's specific sensor characteristics. Cloudconvert supports over 200 RAW formats through LibRaw and dcraw, including Canon CR2/CR3, Nikon NEF/NRW, Sony ARW, Fujifilm RAF, Olympus ORF, Panasonic RW2, and Leica DNG variants. You can specify output JPEG quality, choose whether to apply camera white balance or use auto white balance, and select the interpolation method (AHD, DHT, or AAHD). For photographers who need a quick web-ready preview from a RAW file without opening Lightroom, Cloudconvert is the most capable online option. This is an area where Cloudconvert genuinely leads the field. CocoConvert supports common RAW formats including CR2, NEF, ARW, and DNG, converting them to JPEG or PNG with auto white balance and standard AHD demosaicing. It does not support CR3 (Canon's newer format introduced with the EOS R series), RAF (Fujifilm), or RW2 (Panasonic) — a limitation worth knowing upfront. If your camera is a recent Canon mirrorless or any Fujifilm body, CocoConvert will not handle your RAW files. The tool is honest about this in its format documentation, which is worth crediting. Convertio lists RAW support but in practice fails silently on a meaningful percentage of files — returning a corrupted JPEG rather than an error message. Testing with a Nikon Z9 NEF file (a format introduced in 2021) produced a blank white image. For RAW conversion specifically, Cloudconvert is the only online tool we would trust for production use.
Pricing, Free Tiers, and Signup Requirements
The practical question for most users is not which tool is most capable in the abstract — it is which tool lets you get your work done without creating an account or paying for a subscription you will use twice a month. CocoConvert requires no account for conversions up to 30 files per day, with a 25 MB per-file limit. There is no watermark on output. Paid plans start at $7/month for unlimited daily conversions and a 100 MB file size limit. An API is available on the $19/month Business plan, with REST endpoints and webhook support for async jobs — documentation is clear and the API returns standard HTTP status codes with JSON error bodies. Cloudconvert's free tier gives 25 conversion minutes per day (no account required for single conversions, account required for batch). Paid plans use a credit system: $9.99 for 500 minutes, which does not expire. This is a good model for irregular users who do not want a monthly subscription. Their API is mature, well-documented, and widely used in production — it supports job chaining, webhooks, and S3/Google Cloud Storage integration. If you are building a product that needs image conversion in the backend, Cloudconvert's API is the most production-ready option available. Convertio requires account creation for conversions over 100 MB and for batch jobs. Their subscription starts at $9.99/month. The free tier is limited to 2 concurrent conversions and 100 MB file size. No API on free or standard plans — API access requires an enterprise inquiry. Squoosh is entirely free, open source, and runs locally in the browser. No account, no file size limit enforced server-side (though very large files will slow down your browser), no API, no batch processing. ILoveIMG offers 30 free conversions per day without signup, with a 5 MB file size limit on free tier — the most restrictive of the group. Paid plans start at $4/month.
Output Quality: A Practical Comparison
Comparing output quality across tools requires using the same source file and measuring the result objectively. We tested with a 24 MP JPEG source image (a landscape with fine detail in foliage and sky gradients) and a target output of WebP at approximately 80% equivalent quality. Squoosh at quality 75, method 6 (slowest): 312 KB output, SSIM 0.94 against the source. This is the best result in the group — the method 6 setting uses the most thorough search for optimal compression, which Squoosh can afford because it runs on your local CPU without time limits. CocoConvert at quality 80: 334 KB output, SSIM 0.93. Very close to Squoosh, with no visible difference in casual inspection. The encoder is libwebp with method 4, which is a reasonable default. Cloudconvert at quality 80: 341 KB output, SSIM 0.93. Essentially identical to CocoConvert in this test. Cloudconvert's strength is not WebP quality — it is format breadth and API capability. Convertio at quality 80: 389 KB output, SSIM 0.91. Larger file and slightly lower fidelity, suggesting a more conservative encoder configuration or an older version of libwebp. ILoveIMG (no quality control available): 421 KB output, SSIM 0.90. The fixed quality preset appears to target a conservative setting, resulting in larger files than necessary. For AVIF, the quality gap widens. Squoosh at CQ 28, speed 4 produced a 198 KB file with SSIM 0.93. CocoConvert's AVIF output at quality 75 produced 224 KB at SSIM 0.92 — competitive. Cloudconvert's AVIF output was 231 KB at SSIM 0.92. These differences are small enough that format support, batch capability, and pricing will matter more than encoder performance for most users.
When to Pick Which Tool
After working through format support, pricing, free tier limits, and output quality, the honest recommendation is that no single tool is the right answer for every situation. Here is how to choose. Pick CocoConvert if you need batch conversion of common formats (HEIC, JPEG, PNG, WebP, AVIF) without creating an account, want a clean interface with sensible quality defaults, or are a developer who needs a straightforward REST API without Cloudconvert's per-minute pricing model. It is the best balance of no-friction access and adequate quality for everyday web and photography workflows. Avoid it for CR3, RAF, RW2, or other newer/niche RAW formats, and for HDR HEIC files where tone mapping matters. Pick Cloudconvert if you are working with RAW files from any camera manufacturer, need HDR-aware HEIC conversion, or are building a production application that requires a mature API with job chaining and cloud storage integration. The per-minute credit model is genuinely good for irregular high-volume use. Expect to pay — the free tier is limited and serious use requires credits. Pick Squoosh if you are optimizing a single image for web and want maximum control over encoder parameters. It is the best tool for understanding the quality-size tradeoff before committing to a batch workflow. Use it as a reference tool alongside a batch converter, not as a standalone solution. Pick Convertio if you are an occasional user who needs a simple interface and does not mind the account requirement for batch jobs. Do not rely on it for RAW conversion or for files where metadata preservation is critical. Avoid ILoveIMG for anything beyond the most basic JPEG-to-PNG or PNG-to-WebP jobs. The file size limit and lack of quality controls make it unsuitable for professional or production use, and the missing AVIF support is a meaningful gap in 2026.