JPG to BMP Converter

Add your photos to the box above, pick a colour depth and a size, and press the button. Each picture becomes a real Windows bitmap file in a moment, ready to download on its own or, when there are several, together in one ZIP.

The files are written in your browser by our own BMP encoder, so your pictures are not uploaded anywhere. You can add up to 300 pictures at once, each up to 50 MB, and PNG, WebP, GIF and BMP pictures work as well as JPG. Before you convert, the file list already shows the pixel size each picture will get and the exact size of the BMP file it will become.

JPG is the format of almost every phone and camera photo. It is small because it packs the picture with lossy compression, and a program has to do a fair amount of maths to unpack it again before showing it. BMP is the opposite: the bitmap format of Windows stores the pixels almost exactly as they will appear on screen, row after row, with little or no packing at all.

That simplicity is the reason BMP is still asked for today. A small microcontroller, an LED sign controller, a thermal label printer, an e-paper display or a piece of embroidery or laser software often cannot decode JPG at all, but it can read a BMP with a few lines of code. Old games, Windows programs, boot screens and some industrial machines expect BMP for the same reason.

So people convert photos and logos to BMP when a device or a program will not take anything else, and very often with a strict colour depth or a strict file size. This page is built for exactly that: you choose the depth, the size and, if needed, a limit in KB, and you can see the result before you press the button.

A BMP file, also called a bitmap or DIB (device independent bitmap), starts with two short headers. The file header is 14 bytes and says that this is a BMP and how big the file is. The information header, usually 40 bytes, gives the width, the height, the colour depth and the print resolution. For 8-bit, 4-bit and 1-bit files a colour table, the palette, follows. After that come the pixels.

The pixels are stored from the bottom row to the top row, and each row is padded so that its length in bytes is a multiple of four. Colour pixels are stored as blue, green and red rather than red, green and blue. None of this matters to you as a user, but it explains why BMP files are so easy for small devices to read and why their size can be worked out exactly in advance.

BMP can also be compressed with a simple method called RLE, but many devices and programs do not support it, so this tool always writes uncompressed files. That is the version almost every reader understands.

This JPG to BMP converter free of charge has no sign-up, no watermark, no daily limit and no trial that runs out. You do not need to install anything or create an account, and you can convert as many batches as you like, one after another.

Because the work is done by your own device rather than a paid server, there is nothing to pay for and no queue to wait in. Writing a BMP is very light work for a computer: the slow part is decoding the JPG, and even a batch of a hundred phone photos usually finishes within a minute on a modern laptop.

There are no hidden limits on the output either. The colour depths, the size limits, dithering, DPI and background colour are all available to everyone, for every picture in the batch.

For JPG to BMP 24 bit is the natural choice, and it is the default here. A 24-bit BMP stores three bytes for every pixel, one each for blue, green and red, which gives 16.7 million possible colours. That is the same colour range a JPG photo has, so no colour is rounded or replaced on the way.

It is also the most widely supported kind of BMP. Windows Paint, Photos, Photoshop, GIMP, Paint.NET, IrfanView, LibreOffice, Word and PowerPoint all open it, and so do most programs for embroidery, laser engraving, sign making and industrial printing that accept bitmaps at all. When a program says only BMP and nothing more, a 24-bit file is the safe answer.

The cost is size. A 24-bit BMP takes width × height × 3 bytes, plus a little padding at the end of each row and a 54-byte header. A 1920 × 1080 picture becomes about 5.9 MB, and a 12-megapixel phone photo about 34 MB. If that is too much, make the picture smaller under Size or choose a lower depth.

32-bit + transparency adds a fourth byte to each pixel, the alpha channel, which says how transparent the pixel is. A JPG has no transparency, so for JPG photos 32-bit only makes the file a third bigger than 24-bit without any visible gain. It is meant for PNG, WebP and GIF pictures that do have transparent areas, such as logos, icons and stickers.

This tool writes 32-bit files with the BITMAPV4 header, the newer header that states clearly which bytes hold red, green, blue and alpha. Windows, Photoshop, GIMP, Paint.NET and most modern programs read that header and show the transparent areas correctly.

Be aware that alpha in BMP has a mixed history. Some older programs and many devices read a 32-bit BMP but ignore the fourth byte, so the transparent areas appear black, white or in whatever colour was stored underneath. If you are not sure that the receiving program understands alpha, use 24-bit and pick the background colour under More options instead.

Many devices ask for 256 colours, and this is where JPG to BMP 8 bit conversion comes in. An 8-bit BMP stores one byte per pixel, and that byte points into a palette of up to 256 colours kept in the file. The file is about a third of the 24-bit size, which is why LED controllers, small displays, old games and some firmware tools prefer it.

A photo has many thousands of different colours, so 256 have to be chosen to stand in for all of them. This tool chooses a new palette for every picture, based on the colours that picture actually contains. A sunset gets mostly oranges and blues, a forest mostly greens. That gives much better results than a fixed palette shared by all pictures.

With only 256 colours, smooth areas such as sky, skin or shadows can show bands where one colour jumps to the next. Dithering, which is on by default for 8-bit, mixes neighbouring palette colours in a fine pattern so the eye sees a smooth shade instead. For logos, icons and pictures with flat colours, turn dithering off: the edges stay clean and the file looks crisper.

8-bit grey writes the same compact 8-bit file, but the palette holds 256 even steps from black to white. Each pixel is turned into its brightness, so the picture becomes a smooth black and white photo with no visible steps. It is the usual choice for e-readers, grey e-paper panels, some medical and industrial displays and any device with a grey screen.

Because the palette is fixed and has every grey, no dithering is needed and none is applied to the tones. The file is about a third of the size of a 24-bit BMP. If you only want a grey picture in a common format and not a BMP, Grayscale Image does that for JPG and PNG.

4-bit, 16 colours stores two pixels in each byte, so the file is about a sixth of the 24-bit size. Like 8-bit, the 16 colours are chosen for each picture. Sixteen colours are enough for simple logos, signs, icons and pixel art, and with dithering even a photo stays recognisable, although grainy.

Few modern programs ask for 4-bit BMP, but some old Windows software, small colour displays, embroidery and sign software and older game tools do. Use it when a device names 16 colours or 4 bits per pixel, not as a way to make photos smaller in general.

A JPG to BMP monochrome file uses a single bit per pixel: every pixel is pure black or pure white, with no grey and no colour. It is the smallest BMP you can make, eight times smaller than 8-bit and 24 times smaller than 24-bit, and it is what thermal receipt and label printers, e-paper price tags, some LED matrix boards, laser engravers and many embroidery and vinyl cutting programs expect.

There are two ways to turn a photo into black and white, and this tool offers both. Without dithering, a threshold decides: pixels brighter than the threshold become white, darker ones black. Move the slider until text and lines look clean. This is right for logos, signatures, text, QR codes and line art.

With dithering, the shades of the photo are kept as patterns of black and white dots, like a newspaper picture. Seen from a normal distance, the photo still shows light and shadow. This is right for photos and portraits printed on thermal paper or shown on e-paper. Remember that all colour is lost in 1-bit: a red logo on a blue background may turn into black on black, so check the result.

Dithering is a trick to show more shades than a file can store. When a pixel has to be rounded to the nearest colour in the palette, the difference, called the error, is not thrown away but passed on to the neighbouring pixels that have not been handled yet. Those pixels then round a little the other way, and over a small area the average colour comes out right.

This tool uses Floyd–Steinberg dithering, the classic method. It passes seven sixteenths of the error to the pixel on the right, three sixteenths to the pixel below left, five sixteenths straight below and one sixteenth below right. The result is a fine, even grain rather than a regular grid, and it keeps detail well.

Dithering is offered for 8-bit colour, 4-bit and 1-bit. It is not needed for 24-bit, 32-bit or 8-bit grey, because those store every shade the picture has. Turn it on for photos and smooth gradients, and off for flat logos, text, pixel art and anything that will be traced, cut or engraved, where the dots would get in the way.

Unlike JPG or PNG, a BMP file has no compression, so its size does not depend on what the picture shows. A white page and a busy forest of the same pixel size and depth give exactly the same file size. That makes BMP size easy to calculate, and it is why this tool can show the exact size of every file before converting.

The formula is: header + palette + row size × height. The row size is width × bits per pixel, divided by eight, then rounded up to the next multiple of four bytes. The header is 54 bytes for 24-bit files, and 122 bytes for 32-bit files with the BITMAPV4 header. The palette adds 1,024 bytes for 8-bit files, 64 bytes for 4-bit and 8 bytes for 1-bit.

Row padding is the one detail that surprises people. Each row of a BMP must take a multiple of four bytes. A 24-bit row 101 pixels wide needs 303 bytes, so one empty byte is added to make 304. For widths that are multiples of four, there is no padding at all in 24-bit and 8-bit files.

In 1-bit files the effect is easier to see: a row of 600 pixels needs 75 bytes, which is padded to 76. Over 800 rows that is 800 extra bytes. It is a small amount, but when a device has a strict limit or a fixed buffer, it is worth knowing. The sizes shown in the file list already include the padding, the header and the palette.

Choose File size limit under Size to make every BMP fit under a number of kilobytes. You can pick 100 KB, 128 KB, 200 KB or 500 KB, or type any limit under Custom. Because the size of a BMP depends only on its pixels and its depth, the tool can find the largest picture that still fits, keeping the proportions, without guessing or trying again and again.

If the picture already fits under the limit at its original size, it is left as it is; the limit never makes a picture bigger. If it does not fit, the width and height are reduced together until the file is as close to the limit as possible without going over. The file list shows the new pixel size and the exact file size before you convert.

The most useful thing to know is that the colour depth decides how many pixels fit. Under the same limit an 8-bit file holds three times as many pixels as a 24-bit one, and a 1-bit file holds 24 times as many. So when a limit makes your picture too small to be useful, lower the depth rather than accepting a tiny picture.

A JPG to BMP 100 kb limit is common on upload forms for older systems, on some LED sign and display controllers and in firmware tools with a small memory. 100 KB is 102,400 bytes. At 24-bit that is room for about 34,000 pixels, roughly 213 × 159 for a photo in 4:3 shape: fine for an icon or a thumbnail, small for anything else.

At 8-bit colour or 8-bit grey the same 100 KB holds about 367 × 275 pixels, at 4-bit about 520 × 390, and at 1-bit monochrome over 1000 × 775. If the receiving device accepts a lower depth, that is the way to keep a usable picture under the limit.

Another limit people meet often is 128 KB, which is 131,072 bytes. It shows up in LED matrix controllers, small embedded displays, boot logo tools and some programs for machines with a fixed memory block. For JPG to BMP 128 kb files, pick File size limit and then 128 KB, and every picture in the batch is fitted to it.

At 24-bit, 128 KB holds a 4:3 picture of about 241 × 180 pixels. At 8-bit it is about 416 × 312, at 4-bit about 590 × 442 and at 1-bit about 1181 × 885. Check what your device can show: there is no point in making a 1181-pixel-wide file for a display that is 128 pixels wide. In that case use Width × height with the exact screen size instead.

A JPG to BMP for e-reader conversion is usually about a custom cover or a sleep screen picture. Several e-readers, as well as reading apps and older devices, show pictures best when they are greyscale BMP files at the exact size of the screen, because then the device does not need to scale or convert anything.

Choose 8-bit grey under Colour depth and E-reader 600 × 800 under Size. 600 × 800 is the screen of many classic 6-inch e-readers. Newer models have sharper screens, such as 758 × 1024, 1072 × 1448 or 1264 × 1680, and some models want a different size or a different format entirely, so check your device's manual or support pages for the right size and type in its numbers under Width × height.

Under More options, Fit for exact sizes decides what happens when the photo has a different shape from the screen. Fit whole picture keeps the whole photo and fills the empty sides with the background colour, Crop to fill fills the screen and trims the edges, and Stretch fills the screen by distorting the picture. For covers, Crop to fill usually looks best.

The right depth depends entirely on what will read the file. The table below is a starting point for the most common reasons people need a bitmap. When the device's manual names a depth or a size, follow the manual; it knows the hardware better than any general table.

Small boards with a display, such as the many TFT and OLED screens used in hobby and industrial projects, often load pictures from an SD card or from flash memory. Their libraries usually read uncompressed BMP, most often 24-bit, and sometimes 8-bit or 1-bit. Few of them read JPG, and almost none read the compressed RLE kind of BMP, which is why this tool never writes it.

Make the picture exactly the size of the screen with Width × height, choose the depth the library supports, and leave transparency off, because most display libraries ignore alpha. For one-colour OLED screens, 1-bit monochrome with the threshold or with dithering gives a file the display can show directly. Bottom-up row order, the BMP standard, is what these libraries expect.

Thermal receipt and label printers print one colour, black, on heat-sensitive paper. Their logo and picture tools usually take a 1-bit BMP, and the width of the picture should match the dots of the print head: often 384 dots for 58 mm paper and 576 dots for 80 mm paper. A wider picture is cut off or scaled by the printer, often badly.

Choose 1-bit monochrome, then Width × height with the print head width and a height that keeps the shape of your logo. Use the threshold for logos and text and dithering for photos. Thermal paper does not show fine grey well, so photos printed this way always look like newspaper pictures; that is normal.

Embroidery, laser engraving, vinyl cutting and some CNC programs import bitmaps to trace or to engrave. Many of them accept BMP more reliably than JPG, and for tracing they work best with a clean black and white picture. Choose 1-bit monochrome without dithering and move the threshold until the lines are solid and the background is white.

For engraving photos on wood or stone, some laser programs prefer a dithered 1-bit picture, because the laser can only burn or not burn each dot. Others take an 8-bit grey picture and dither it themselves. Read what your program recommends and pick the matching depth here.

Older games, mods, level editors and Windows programs from the 1990s and 2000s often use BMP for textures, icons, splash screens and skins, very often at 8-bit with a palette, at a fixed size. If a tool refuses your file, compare it with an original file from the game: the width, the height and the depth should match.

Some of these programs use one colour, often magenta, as a transparent colour instead of an alpha channel. You can create that with the background colour under More options when your source is a transparent PNG: set the background to the colour the game treats as transparent and save a 24-bit or 8-bit file.

People often look for JPG to BMP high quality conversion and expect the bitmap to look better than the photo. It is worth being clear: converting cannot bring back detail that JPG compression already removed. Blocky edges, smeared colours or the halos around text in a heavily compressed JPG will still be there in the BMP.

What 24-bit and 32-bit conversion do guarantee is that nothing more is lost. Every pixel of the decoded JPG is copied into the BMP exactly. From then on the bitmap can be opened and saved as often as you like without any change. 8-bit, 4-bit and 1-bit files reduce the number of colours by design, which is a choice you make for a device, not a loss of quality you have to accept for everything.

When the picture is made smaller, the tool reduces it in halves, step by step, before the final size. Doing big reductions in one jump can leave jagged edges and shimmering patterns; halving keeps the result sharp and smooth. For the best result start from the original photo from the camera or phone, not a copy sent through a messaging app.

Messaging apps and social networks make photos smaller and compress them again before sending, and each of those steps removes detail. A photo saved from a chat may be a quarter of the pixel size of the one on the sender's phone, with visible artefacts. Ask for the original file or copy it straight from the camera or phone by cable or cloud storage.

If the JPG has a much larger pixel size than you need, that is not a problem: the tool reduces it carefully, and a reduced picture often looks cleaner because small artefacts are averaged away.

Everything on this page works for PNG to BMP as well, and also for WebP, GIF and existing BMP files. Add them to the same box and they are converted with the same settings. PNG pictures are often logos and screenshots with flat colours, which suit 8-bit and 4-bit files particularly well, usually with dithering off.

The difference is transparency. Many PNG files have transparent areas. With 32-bit + transparency, those areas stay transparent in the BMP, written with the BITMAPV4 header. With any other depth, transparent areas are filled with the background colour you pick under More options, white by default.

If the program reading the BMP shows a black background where the PNG was transparent, it does not read the alpha channel. Convert again with 24-bit and the background colour of your choice. To go the other way, BMP to PNG turns bitmaps back into compact lossless PNG files.

This JPG to BMP online free tool runs in any modern browser on Windows, macOS, Linux, ChromeOS, iPhone, iPad and Android. There is no app to install and no plug-in. On a phone, tap the box to pick photos from the gallery or the files app, convert, and save the BMP to your files.

Phones can be slow with very large photos and big batches, because everything is done on the device. If a phone struggles, convert ten or twenty pictures at a time. On a computer, batches of hundreds of photos are no problem.

Note that iPhone photos are often HEIC rather than JPG. Many iPhones convert them to JPG automatically when you share or pick them in a browser; if yours does not, change the camera format to Most Compatible in the settings, or convert the HEIC files to JPG first.

Add up to 300 pictures at once, each up to 50 MB. All of them get the same depth, size and options, and the list shows the planned pixel size and the exact BMP file size of each picture before you start. When the batch is done, download each BMP on its own or all of them together in one ZIP file.

The BMP files keep the names of your pictures with the .bmp ending. You can stop a running batch at any time, and press Ctrl + Enter, or Cmd + Enter on a Mac, to start converting without reaching for the button.

Under Size, Original keeps every pixel of the picture. Width × height makes every picture exactly the size you type, which is what most displays, signs and printers need. E-reader 600 × 800 is a shortcut for the classic e-reader screen. File size limit makes the largest picture that stays under a number of kilobytes.

When a picture has a different shape from the width and height you type, Fit for exact sizes under More options decides what happens: fit the whole picture with empty sides, crop to fill the area, or stretch. If you just need to make photos smaller in a common format without making BMP files, Resize Image does that for JPG, PNG and WebP.

Under More options you can choose the DPI stored in the BMP: 72, 96, 150 or 300. The default is 96, the value Windows traditionally assumes. DPI is only a number in the header that tells printing and layout programs how large to print the picture; it does not change the pixels or the file size.

Most devices and programs ignore it completely. Set it only when a print or layout program uses it to size the picture on paper, for example 300 DPI for a picture that should print sharp at its pixel size divided by 300 inches.

The background colour is used in two cases. The first is transparent pictures such as PNG logos converted to any depth except 32-bit: the transparent areas are filled with this colour. The second is Fit whole picture with an exact size: the empty sides above and below, or left and right, are filled with it.

White is the default. Choose black for e-readers and displays with a dark theme, or the exact colour of your sign, screen or game that should show through. For 1-bit files remember that the background will become pure black or pure white after the threshold.

You can also save a JPG as BMP with programs already on your computer. On Windows, open the photo in Paint, choose Save as, then BMP picture. Paint also offers 256-colour, 16-colour and monochrome bitmaps in the Save as type list, but it does not let you pick the palette, dithering or an exact file size. On a Mac, Preview can export BMP from the File menu.

Those ways work for a single picture. They become slow for a whole folder, they do not show the file size before saving, and they offer no size limit in KB, no e-reader size and no control over dithering. This page does all of that for a batch at once, with the same settings for every picture.

On Windows, BMP files open in Photos and Paint, and they show as thumbnails in File Explorer. On a Mac, Preview opens them. Image editors such as Photoshop, GIMP, Paint.NET, Affinity Photo and IrfanView open every depth this tool writes. Web browsers can show BMP files too, but they are not meant for web pages, because they are so large.

To check a file before you send it to a device, look at its properties. On Windows, right-click the file, choose Properties and the Details tab to see the width, height and bit depth. On a Mac, Preview's Inspector shows the same. The sizes in the tool's list and in the download list should match exactly.

Which depth does the device or program read: 1, 4, 8, 24 or 32 bits?

Does it need an exact width and height, or a file size limit?

Does it read transparency, or should transparent areas get a background colour?

Is the picture a photo (dithering on) or a logo or text (dithering off)?

Have you checked one finished file on the device?

Your pictures are not uploaded. The page loads once, and after that the decoding, resizing, colour reduction and BMP writing all happen inside your browser, on your own device. No copy of your photos is sent to FlipMyFormat or anyone else, and nothing is stored when you close the tab.

That makes the tool suitable for private photos, family pictures, product designs, company logos and anything else you would rather not hand to a website. You can even disconnect from the internet after the page has loaded, and it keeps working.

Each picture is decoded by your browser, the same way it shows images on any page. If you chose a smaller size, the picture is reduced in halves until it is close to the target, then scaled to the exact size, which keeps edges sharp. For 8-bit and 4-bit, a palette is built from the colours of that picture, and each pixel is matched to the nearest palette colour, with Floyd–Steinberg dithering if it is on.

Finally our own encoder writes the BMP: the file header, the information header (the BITMAPV4 header for 32-bit), the palette where needed and the pixel rows from bottom to top, each padded to four bytes. The finished files are offered for download, one by one or in a ZIP.

Find out the exact depth and size your device needs before converting; it saves trial and error.

Make the picture the exact screen size rather than letting a small device scale it.

Use dithering for photos and turn it off for logos, text and line art.

Use 8-bit grey rather than 8-bit colour for grey displays and e-readers: it gives smoother tones.

For 1-bit logos, increase contrast in an editor first if the threshold alone does not give clean lines.

Keep the original JPG; the BMP is a working copy for the device.

Test one file on the device before converting a whole batch.

Copy the BMP files to the device, SD card or program that needs them. If you later want a compact copy for sharing, BMP to PNG makes a lossless PNG and BMP to WebP a much smaller WebP. BMP to PDF puts bitmaps into a PDF document for printing or sending.

For other lossless formats, JPG to PNG and JPG to TIFF keep every pixel at a fraction of the size, and PNG to TIFF suits print and archive work. To shrink JPG photos without changing their format, use Compress Image. You will find all of these under Image Tools.