Raw RFC 1951 DEFLATE restricted to fixed-Huffman blocks. The encoder emits a single BFINAL=1, BTYPE=01 block over the fixed literal/length and distance alphabets of section 3.2.6, with LZ77 matching across a 32 KiB window; no dynamic code lengths are ever transmitted. Output is a conforming raw DEFLATE stream that any inflater reads. The decoder handles stored and fixed blocks; dynamic blocks are the full DEFLATE implementation’s job.
| Property | Value |
|---|---|
| Category | Compression Algorithms |
| Sub-category | Dictionary + Entropy Coding |
| Security status | 🎓 Educational Only |
| Complexity | Intermediate |
| Inventor | Phil Katz |
| Year | 1991 |
| Origin | 🇺🇸 United States |
| Source | algorithms/compression/deflate-simple.js |
Status: 🎓 Educational Only
No vulnerabilities are recorded for this implementation.
7 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Empty input - bare final fixed block with end-of-block only
| Field | Value |
|---|---|
input |
(empty) |
expected |
0300 |
Vector 2 — Single literal - 0x30+65 then end-of-block
| Field | Value |
|---|---|
input |
41 |
expected |
730400 |
Vector 3 — Literal then length 7 at distance 1 - overlapping match
| Field | Value |
|---|---|
input |
4141414141414141 |
expected |
73840200 |
Vector 4 — Three literals then length 6 at distance 3
| Field | Value |
|---|---|
input |
414243414243414243 |
expected |
737472862000 |
Vector 5 — Repeated phrase round-trip
Source: Regression test for match emission
| Field | Value |
|---|---|
input |
74686520717569636b2062726f776e20 666f78206a756d7073206f7665722074 6865206c617a7920646f672e20746865 20717569636b2062726f776e20666f78 206a756d7073206f7665722074686520 6c617a7920646f672e |
expected |
(empty) |
Vector 6 — All 256 byte values round-trip
Source: Regression test for the 9-bit literal range
| Field | Value |
|---|---|
input |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f 404142434445464748494a4b4c4d4e4f 505152535455565758595a5b5c5d5e5f 606162636465666768696a6b6c6d6e6f 707172737475767778797a7b7c7d7e7f 808182838485868788898a8b8c8d8e8f 909192939495969798999a9b9c9d9e9f a0a1a2a3a4a5a6a7a8a9aaabacadaeaf b0b1b2b3b4b5b6b7b8b9babbbcbdbebf c0c1c2c3c4c5c6c7c8c9cacbcccdcecf d0d1d2d3d4d5d6d7d8d9dadbdcdddedf e0e1e2e3e4e5e6e7e8e9eaebecedeeef f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff |
expected |
(empty) |
Vector 7 — Long run round-trip
Source: Regression test for maximum match length
| Field | Value |
|---|---|
input |
5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a 5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a 5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a 5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a … (1024 bytes; the full value is in the source) |
expected |
(empty) |