Online Image Viewer & Image Converter with HDR support

Open Image Panel

To use Image Convert Ninja, you need to open an image first.

You can do this in two ways. You can either click the big blue OPEN IMAGE button or drag and drop your image file into the Image Viewer.

The Image Viewer will show your image instantly or after a short wait, depending on its format, size, and your device's speed. You will see a spinning icon while it loads. When it's done, you can start using the tool. The friendly blue ninja will help you view, convert, and adjust your image.

Once you upload your first image, the button name will change to CHANGE IMAGE. This means you can add another image without reloading the page. You can upload as many images as you want in one session.

If you are on a phone, you can only use the OPEN IMAGE button, because phones don't support drag and drop.

If you are on a new iPad, you can use the Split View feature to split the screen between the browser and the Files app. Then, you can drag and drop images from your tablet's file system into the browser. You can also do this if your device supports Samsung DeX.

HDRI Exposure Panel

When you open an HDR or EXR file, you can use the HDRI Exposure panel to change how bright or dark your image looks. You can choose an exposure value from 0.01 to 4 by using the slider or typing the number in the input field above.

HDR images contain information about a wide range of brightness, from very dark to extremely bright. A normal screen can't display all the brightness at once, so you have to choose the part of the brightness range you want to see. Either the one in the dark zone or the one in the bright zone. This is called exposure tone mapping.

The lower the exposure value, the darker the image. The higher the exposure value, the brighter the image. The default value is 1.

Most HDR images look good at the default value of 1. You should only change this value if you really need to. For example, if your image is too bright or too dark, you can lower or raise the exposure to make it better. You can see the exposure change in real time in the Image Viewer.

When you save your image in a non-HDR format, it will keep the exposure that you selected. The saved image will look the same as it does in the Image Viewer.

You can't use tone mapping on a regular 8-bit image like PNG, JPEG, etc. It won't work because an 8-bit image only has a limited range of brightness levels. Changing this range will not reveal more details, but will just cut off some of them and make your image worse. That's why the HDRI Exposure panel is inactive when you use images other than HDR or EXR.

Tip

If you want to learn more about HDR and LDR, we have a great tutorial for you. It's called HDRI - Ultimate Control Over Exposure. It's mainly for CG artists, but anyone can understand it. It explains these concepts with photography examples. You can read the main part of the tutorial in a few minutes and get the idea.

In short, LDR means Low Dynamic Range. It's the type of images that you usually see on screens and web pages. They have 8 bits per pixel, which means they can store a limited amount of information about the color of each pixel. The more bits per pixel, the more information you can store. There are also 16-bit images, which are better than 8-bit, but still not as good as HDR.

HDR means High Dynamic Range. It's the type of images that have 32 bits per pixel, which means they can store a lot more information about the color of each pixel. They can capture a wider range of brightness levels, from very dark to very bright.

You can also read a good article about HDRI on Wikipedia, here and here.

Compression Panel

The Compression / Quality panel allows you to choose how much you want to reduce the size of the image file by reducing its quality. Using the slider or the input field, you can set the compression level from 0% to 100%. The lower the compression level, the smaller the file size, but the worse the quality. The higher the level, the larger the file size, but the better the quality.

The Compression / Quality panel is only active when you've chosen a compressible format to save your image, such as JPEG or WebP. These formats use a lossy compression technique, which means they discard some details of the image to reduce its size. All other output formats are lossless formats, which means they preserve all the details of the image, but at the expense of its size. That's why the Compression / Quality panel is grayed out when you choose lossless output formats.

In some browsers, image compression may not work as expected. For example, on the iPad, Chrome can save WebP, but it ignores the quality level for it. This means that if you save WebP, the file size will remain the same no matter what quality level you choose. On the other hand, everything works flawlessly in the desktop version of Chrome.

Save Image Panel

The Save Image panel lets you select a conversion format and eventually save the converted image to your device.

Format

This is a drop-down list with available formats for saving the image. Here you can choose between compressible and lossless formats. The default format is JPEG. If you select one of the compressible formats, the Compression / Quality panel will become active, where you can also choose the desired compression level.

Copy Base64

This is a button that copies the image as a Base64-encoded URL to the clipboard. You can use this feature, for example, to insert an image into HTML or CSS code [background: url( Base64 image string goes here... )], or to share it online without saving it as a file. This button is only active when you've selected JPEG, WebP, or PNG as the output format.

Save Image

This is a button that saves the image file to your device. When you click this button, Image Convert Ninja will start converting the image to the format of your choice. This may happen instantly or take some time, depending on the size of the image and the actual performance of your device. While the image is being prepared, the button text will temporarily change to "Preparing Image" with a rotating circle next to it. When the image is ready, Image Convert Ninja will open a standard browser dialog box where you can choose where to save the file on your device.

Image Convert Ninja will use the same name as the image file you uploaded as the name of the saved file. If you select a compressible format such as JPEG or WebP and change the compression level from 100%, Image Convert Ninja will prepend the file name with "_[n][n]", where [n][n] is the compression level you selected.

Note

Please note that Image Convert Ninja can only save images in web formats like PNG, JPEG, etc. It cannot save images in other formats like TIFF, HDR, or EXR.

Also, Image Convert Ninja does not keep the transparent parts of the image when it changes it to another format. It fills them with a background color instead. This is something I am working on fixing.

Image Viewer

Image Viewer lets you see the images you upload right on the page. You don’t need any extra software or plug-ins. The tool uses the power of your device’s GPU (using WebGL), so it is as good as, or even better than, some desktop image viewers.

You can use Image Convert Ninja because of Image Viewer alone, without using the format conversion features at all. You can also use it on mobile devices like smartphones and tablets, which usually don’t have good image viewer software. They usually only have a standard photo gallery app. For instance, Image Convert Ninja's Image Viewer can handle TIFF, HDR or EXR formats, which most mobile photo viewers don’t support.

Controls Lock

When you open your first image, and it is loaded in the Image Viewer, you can start working with it.

By default, the Image Viewer controls are locked. This is on purpose to make sure that the zoom and pan features in the Image Viewer don’t accidentally mess with the page scrolling.

For example, if the Image Viewer controls are unlocked, when you move the mouse over the Image Viewer and then try to scroll the page using the wheel, you’ll zoom in and out of the image in the Image Viewer instead of scrolling the page. Likewise, on a mobile device, when you swipe with your finger over the Image Viewer with the controls unlocked, you’ll move the image instead of scrolling. This can be confusing at first, that’s why the controls are locked by default.

If you want to unlock the Image Viewer controls, use the padlock icon in the lower left corner of the Image Viewer.

Panning

To pan or move the image in any direction inside the Image Viewer, you can click or tap on the image and drag it to where you want. You can use the left mouse button or your finger if you are on a mobile device.

Zooming

To zoom in or out, you can scroll the mouse wheel or use pinch gestures on the image. You can do this on any part of the Image Viewer.

Reset View

Double-click or double-tap anywhere in the Image Viewer to fit an image into the current frame of the Image Viewer viewport.

Full Screen Mode

To see the image in full screen mode, you can click the button with a square icon at the top right corner of the Image Viewer. This will make the Image Viewer fill the whole screen of you device. Now you can enjoy the image in full size.

To go back to the normal mode, you can click the button again or press the Esc key if you are on a computer.

If you are using an iPad, moving the image in full screen mode can be a bit tricky. When you switch to full screen mode on your iPad, you will see this message:

“rendersnail.com” is in full screen. Swipe down to exit.

This means that if you move your finger down quickly, iPadOS will register this motion as a "swipe down" gesture, which will cause you to exit full screen mode.

To pan an image in full screen mode on iPad:

Switch to full screen mode in the browser on your iPad.
Press and hold your finger on the image.
Wait a moment, then move your finger in any direction to pan the image.

On smartphones, full screen mode is not available. That's because it doesn't make sense on small screens because on a mobile phone you will already have Image Viewer fame at the full width of a screen, and switching to full screen won't make any difference. In addition, smartphone browsers do not support full screen well, which can lead to a white screen instead of content, as well as unexpected page reloads.

Input Formats

Image Convert Ninja supports all major web formats as well as additional formats that are typically considered desktop-only.

Web formats

These are formats used on web pages as online images. They include JPEG, WebP, AVIF, PNG, APNG, GIF, SVG, BMP, and ICO.

Some of these formats, such as PNG, GIF, WebP, AVIF, and SVG, may contain an alpha channel. The checkerboard backdrop will be visible in the Image Viewer viewport through the parts of the image affected by the alpha.

The APNG and GIF formats can contain animation. However, Image Convert Ninja will only show the first frame and ignore the rest.

Desktop Formats

These types of files are often found exclusively in desktop software, but the online Image Convert Ninja tool can open 8-bit TIFF, 32-bit HDR, and 32-bit EXR files right in your browser.

Tip

The EXR format is a very advanced and complex format that can store multiple layers (including cryptomatte layers), an alpha channel, can have different types of compression, different color depth values, and other information. EXR implementation and settings may differ from program to program that generate it. As a result, some EXR files may not be compatible with other programs. If you can't open an EXR file with Image Convert Ninja, it may be because the image resolution is too high for your browser or the EXR file has unusual or proprietary settings. Although it is unlikely, it is still possible.

If Image Convert Ninja can't open some EXR file, chances are you won't be able to open it, even in an ultimate image processing tool like Photoshop.

I ran into the same problem when when I tried to read EXR files created by the V-Ray plugin for 3ds Max in Photoshop. Some files worked flawlessly, while others would not open.

However, I found a simple solution. There is a free Photoshop plugin called Exr-IO that can open most EXR file configurations. Just install it in Photoshop and reopen the "corrupted" EXR file. Photoshop should now open it correctly.

As you might expect, Image Convert Ninja also cannot open this type of EXR file by itself. However, if you open such a file in Photoshop with the Exr-IO plug-in loaded and then save it again, Image Convert Ninja will easily handle the re-saved version of the EXR file.

Maximum Resolution

Browsers themselves limit the maximum size of an image that can be uploaded to them. For desktop browsers based on Chromium, it is about 32K. For Firefox and mobile browsers, this limit is lower and depends on the browser.

In addition, Image Convert Ninja uses WebGL and treats images as textures, so the maximum resolution it can process is limited by the browser's Maximum Texture Size property. The value of this property depends on your browser and graphics processor. For desktop browsers based on Chromium, it is about 16K (16384px on the larger side). In Firefox, this limit is 8K (8192px on the larger side). For mobile devices, it will be even lower.

This means that even if you open, say, a 20K image, Image Convert Ninja will reduce it to 16K/8K and so on.

Output Formats

You can save the image in these formats:

Compressible

JPEG and WebP.

Lossless

PNG, GIF, BMP, AVIF and ICO.

Maximum Output Resolution

The maximum output resolution is the size of the image you'll save to your device after the conversion. This size is limited by your browser's so-called Drawing Buffer. This property determines the largest image that can be displayed on a web page. For desktop browsers, it is usually limited to a size of about 8K. For mobile devices, it can be smaller.

If you open an image that is larger than the Display Buffer supported by your browser, Image Convert Ninja will process it, but will automatically reduce the image resolution to fit your browser's limitations.

Performance

Image Convert Ninja is a powerful web-based program that works with images by using the power of your device. It makes use of both the CPU and the GPU. This implies that the speed of uploading, processing, and saving images is directly determined by the speed of your device and the size of the images you use.

If you are opening a very large image of several hundred megabytes, Image Convert Ninja will handle it, but it will take some time.

If you are dealing with a very large image, the processing may take several seconds, which exceeds the process execution time limit of your browser. In response to this, your browser may think that Image Convert Ninja is "frozen" and not working properly. Then it will show you a prompt that says "Page not responding" and ask you to "Wait" or "Exit" the page. In this case, you don't need to do anything, just wait for the image to load. The browser will close this window by itself.

Security

Image Convert Ninja is technically a client-side only program that runs exclusively in your browser. It does not use a server to process images, but instead uses the power of your device. Since all image processing takes place locally in your browser, Image Convert Ninja is completely private and secure. It doesn't even require an internet connection, except for the one-time download of this page. No one but you know what images you are viewing or converting here.

About

Image Convert Ninja is a web tool that lets you observe and convert images online. You can enjoy your photos and other images in full detail and quality, without downloading or installing anything. You can also change them to different formats, such as JPEG, PNG, WebP, etc. plus TIFF. But what makes it really special is that it can open and show 32-bit HDR and EXR images. You can adjust the brightness of these images and preview them in high resolution in real time right in your browser.

You can also copy the images you convert to your clipboard as base64 code. This means you can easily paste the images into other apps or web pages without saving them as files.

This tool is easy and fun to use on any device. You can zoom in and out, pan or move the image with your mouse or fingers. The Image Viewer uses WebGL, which means it uses the power of your GPU to show the images fast and smooth. It can display very large images, up to 16K resolution.

Image Convert Ninja does not use any server processing at all. All the image processing happens in your browser, which means it is completely private and secure. No one but you knows what images you are viewing or converting.

You don't need to register or pay anything to use this tool. It is free and unlimited for everyone.

Let's summarize!

Features

View and convert all popular image formats, including JPEG, PNG, WebP, as well as TIFF, HDR, and EXR.
Adjust the exposure of HDR and EXR images to make them dimmer or brighter.
Preview images in high resolution in real time right in your browser.
Copy converted images in the selected format to the clipboard as base64 Data URL strings.
Pan and zoom images with your fingers on your mobile device.
Go full screen.
Completely private and secure. All image processing takes place in your browser.

Benefits

Fast and easy to use.
No need to download or install anything.
Supports HDR and EXR images.
User-friendly interface.
Private and secure.

Why Ninja?

Image Convert Ninja - Free online image converter with HDRI support.

As you see, Image Convert Ninja logo shows a cartoon ninja hitting a board with the word "Image" written on it. The board breaks into three pieces, labeled .JPEG, .WebP, and .PNG. This symbolizes the tool's ability to convert images to different formats.

The ninja represents speed and accuracy, meaning that Image Convert Ninja is a fast and easy way to view and convert images.

The ninja is also a symbol of stealth and secrecy, meaning that your images are safe and private with Image Convert Ninja.

The ninja is also a master of many skills and techniques. This means that this tool can do more than just viewing and converting images. It can also adjust the brightness and compression level of the images, copy them as base64 code, and show them in high resolution.

Finally, ninja is also a fun and friendly character. The Image Convert Ninja is designed to be easy and enjoyable to use. It has a simple and intuitive interface, with no learning curve for non-professional users.

To put it simply, Image Convert Ninja is a fast, easy, secure, and fun way to view and convert images online.

History

Image Convert Ninja started as a simple image viewer for 32-bit images in 2022. The goal was to provide a cross-platform service for those who need to open HDR or EXR files on Windows, Linux, macOS, iOS or Android devices. The idea was to bring desktop app experience to the web and mobile devices.

But then it became clear that this tool could do more than that. It could also work with conventional 8-bit image formats and offer the user more features and benefits. So this online HDR file viewer became a general purpose online image viewer and converter, with a bonus feature of opening and processing EXR and HDR files.

Image Convert Ninja is not just an online image viewer and converter. It's also a project that aims to fill a gap in free online image processing services. Most existing services either have too limited functionality or are too complicated for non-professional users. Image Convert Ninja solves this problem.

I plan to gradually add more features like color correction, image cropping, etc. But at the same time, I also want to keep the user interface simple and intuitive, without too much clutter and a learning curve. To offer you only what you really need.

Image Convert Ninja is created and maintained by RenderSnail team, that is, by me for now )) It is a web app that uses JavaScript and WebGL to work with images in your browser. It does not need any plug-ins or extra installation on your part.

I am always open to new ideas and feedback. If you have any suggestions or questions about this tool, or if you find any errors while using it, please let me know.

Updates

v3.1.0 (Sep 17, 2023 Update)

The Image Viewer has been enhanced with a full-screen mode feature. Now you can switch it to full screen mode in one click.
The whole Image Convert Ninja documentation has been rewritten from scratch to make it more concise, less verbose, and more user-friendly.

v3.0.0 (Sep 10, 2023 Update)

The layout of the Image Ninja interface and all its individual elements have been totally redone.
The Image Viewer is now on the left, while the control panels are on the right. Only on tiny screens does the Image Viewer take up the full browser window, and all the panels will relocate themselves beneath the Image Viewer automatically.
On medium and large screens, Image Ninja automatically adapts its layout to the available screen space. This way, all Ninja's components are visible at once. This eliminates the need to scroll to get to any part of the interface, whether you want to open a new image or save a converted one.

v2.2.1 (Aug 31, 2023 Update)

The Image Viewer shows the given image against a checkerboard background. If you provide an image with transparency capabilities, i.e. PNG, GIF, WEBP, AVIF or SVG, the checkerboard backdrop will also be visible through the areas of the image affected by the alpha channel.
The ability to use the mouse wheel to change the Tone Mapping Exposure and Compression sliders has been removed. This will prevent you from accidentally altering the sliders positions when scrolling the page with the mouse wheel.
Fixed a bug with the image exposure unexpectedly being reset while navigating the page.

v2.1.0 (Mar 17, 2023 Update)

Image Viewer navigation controls like Zoom and Pan are now locked by default. This will improve the experience of using Image Viewer on mobile devices by allowing users to easily scroll the page by swiping up and down, including across Image Viewer, without interfering with controls.
Image Viewer now has a button with a lock icon in the lower left corner. You may use it to lock and unlock Image Viewer controls.

v2.0.0 (Mar 11, 2023 Update)

The tool has been renamed from "Online Image Converter HDR" to "Image Convert Ninja". Having said that, this program is clearly now more about converting images than viewing them. But, Ninja continues to view images.
The Image Viewer itself has been significantly redesigned. Separate "Full Screen" and "Reset View" buttons have been removed. The full-screen mode capability has been eliminated entirely. Reset View, on the other hand, has developed into a double-click option. By double-clicking anywhere on the Image Viewer, you can now simply reset the view.

Image Convert Ninja

Contents