Add your ICO file
Drop one or more .ico files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Converting a .ico image to .pbm re-encodes the pixels for a different balance of size, quality, and support. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Converting a .ico image to .pbm re-encodes the pixels for a different balance of size, quality, and support. An .ico file is a Windows icon container that bundles the same artwork at several sizes and color depths so the OS can pick the best match for any context. On the web it survives as the classic favicon format, with favicon.ico still the fallback path every browser requests.
A .pbm file is a Portable Bitmap: the simplest image format in common use, storing exactly one bit per pixel — black or white, with no grey and no colour. It carries a two-character magic number, the width and height, and then the pixels, and nothing else. For this route the practical draw is small enough to specify in a paragraph and to write from a shell script and uncompressed and lossless, so nothing is hidden between the header and the pixels — balanced against one bit per pixel — no grey, no colour, no transparency, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .ico, hard 256x256 ceiling makes it useless for general imagery. Switching to .pbm buys you small enough to specify in a paragraph and to write from a shell script, which is why it is the better fit for masks, stencils and other genuinely two-tone raster data. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | Windows icon (.ico) | Portable bitmap (.pbm) |
|---|---|---|
| Format type | Lossless — every pixel or sample is preserved exactly | Lossless — every pixel or sample is preserved exactly |
| How it stores data | a directory header indexes multiple images, each with its own dimensions and bit depth | two encodings share the extension: P1 stores pixels as ASCII 0 and 1 characters, P4 packs eight pixels into each byte |
| Strongest at | website favicons served from the /favicon.ico fallback path | masks, stencils and other genuinely two-tone raster data |
| Weak spot | hard 256x256 ceiling makes it useless for general imagery | one bit per pixel — no grey, no colour, no transparency |
Drop one or more .ico files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .pbm in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if PBM is selectable, the route is real and validated.
Press Convert. Decoding and re-encoding happen on your device using the browser's native image pipeline and hand-tuned encoders.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid PBM file. Outputs keep the original filename with the .pbm extension.
Since ico is lossless-oriented and pbm is lossless-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .pbm itself requires.
Yes — the .ico file is processed inside your browser tab and never uploaded. Decoding and re-encoding happen on your device using the browser's native image pipeline and hand-tuned encoders. Close the tab and the file is gone from memory.
Netpbm, ImageMagick, GIMP and most scientific imaging tools read PBM; browsers and consumer applications do not. Novus Convert decodes both the ASCII and the packed binary form locally and converts to PNG, JPEG, WebP and the other raster targets — which is usually the point, since PBM is a good interchange format and a poor delivery one.
It depends on the content: two encodings share the extension: P1 stores pixels as ASCII 0 and 1 characters, P4 packs eight pixels into each byte. Convert one representative file first and compare before batch-processing a large set.
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .ico → .pbm → .ico is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.