Post-Quantum Algorithm Zoo: Sizes and Speed of 100+ Algorithms
All 103 algorithms that liboqs ships, from the NIST standards to the candidates of the additional-signature round: filter, sort by size, and pick one to measure. The benchmark compiles liboqs to WebAssembly, runs in a background worker on your own device and compares the result with ECDSA P-256, Ed25519 or X25519 measured the same way.
100% local — algorithm code is downloaded from this site only when you measure, and runs in your browser; nothing about your device or the results is sent anywhere
103 algorithms from liboqs 0.15.1: 38 key encapsulation mechanisms and 65 signature schemes, in 15 families.
ML-KEM-768
Sizes next to the classical algorithms
| Algorithm | Public key |
|---|---|
| ML-KEM-768 | 1,184 B |
| X25519 | 32 B |
| Algorithm | Signature / ciphertext |
|---|---|
| ML-KEM-768 | 1,088 B |
| X25519 | 32 B |
Public key plus ciphertext: 35.5× X25519. Classical sizes are raw encodings: uncompressed EC points, r‖s for ECDSA, a PKCS #1 key for RSA-2048.
- Standardised in FIPS 203 (August 2024). The KEM to deploy: TLS, SSH and HPKE already define how to use it.
Measure on this device
Runs key generation and encapsulation and decapsulation in a background worker, about 3 seconds at most per operation, and the same operations of X25519 for comparison. Every result is checked, so a broken build cannot report a fast but wrong number.
103 algorithms of 103
| Algorithm | Family | Status | Level | Public key | Private key | Signature / ciphertext | Key + output (log scale) |
|---|---|---|---|---|---|---|---|
| SLH-DSA | NIST standard | 1 | 32 B | 64 B | 17,088 B | ||
| SLH-DSA | NIST standard | 1 | 32 B | 64 B | 7,856 B | ||
| SLH-DSA | NIST standard | 1 | 32 B | 64 B | 17,088 B | ||
| SLH-DSA | NIST standard | 1 | 32 B | 64 B | 7,856 B | ||
| SLH-DSA | NIST standard | 3 | 48 B | 96 B | 35,664 B | ||
| SLH-DSA | NIST standard | 3 | 48 B | 96 B | 16,224 B | ||
| SLH-DSA | NIST standard | 3 | 48 B | 96 B | 35,664 B | ||
| SLH-DSA | NIST standard | 3 | 48 B | 96 B | 16,224 B | ||
| CROSS | NIST candidate | 1 | 54 B | 32 B | 9,120 B | ||
| CROSS | NIST candidate | 1 | 54 B | 32 B | 11,980 B | ||
| CROSS | NIST candidate | 1 | 54 B | 32 B | 8,960 B | ||
| SLH-DSA | NIST standard | 5 | 64 B | 128 B | 49,856 B | ||
| SLH-DSA | NIST standard | 5 | 64 B | 128 B | 29,792 B | ||
| SLH-DSA | NIST standard | 5 | 64 B | 128 B | 49,856 B | ||
| SLH-DSA | NIST standard | 5 | 64 B | 128 B | 29,792 B | ||
| CROSS | NIST candidate | 1 | 77 B | 32 B | 13,152 B | ||
| CROSS | NIST candidate | 1 | 77 B | 32 B | 18,432 B | ||
| CROSS | NIST candidate | 1 | 77 B | 32 B | 12,432 B | ||
| CROSS | NIST candidate | 3 | 83 B | 48 B | 22,464 B | ||
| CROSS | NIST candidate | 3 | 83 B | 48 B | 26,772 B | ||
| CROSS | NIST candidate | 3 | 83 B | 48 B | 20,452 B | ||
| CROSS | NIST candidate | 5 | 106 B | 64 B | 40,100 B | ||
| CROSS | NIST candidate | 5 | 106 B | 64 B | 48,102 B | ||
| CROSS | NIST candidate | 5 | 106 B | 64 B | 36,454 B | ||
| CROSS | NIST candidate | 3 | 115 B | 48 B | 29,853 B | ||
| CROSS | NIST candidate | 3 | 115 B | 48 B | 41,406 B | ||
| CROSS | NIST candidate | 3 | 115 B | 48 B | 28,391 B | ||
| CROSS | NIST candidate | 5 | 153 B | 64 B | 53,527 B | ||
| CROSS | NIST candidate | 5 | 153 B | 64 B | 74,590 B | ||
| CROSS | NIST candidate | 5 | 153 B | 64 B | 50,818 B | ||
| NTRU | Not selected by NIST | 1 | 699 B | 935 B | 699 B | ||
| CRYSTALS-Kyber | Superseded | 1 | 800 B | 1,632 B | 768 B | ||
| ML-KEM | NIST standard | 1 | 800 B | 1,632 B | 768 B | ||
| Falcon | Selected by NIST, standard in preparation | 1 | 897 B | 1,281 B | ≤ 752 B | ||
| Falcon | Selected by NIST, standard in preparation | 1 | 897 B | 1,281 B | 666 B | ||
| NTRU | Not selected by NIST | 3 | 930 B | 1,234 B | 930 B | ||
| SNOVA | NIST candidate | 1 | 1,016 B | 48 B | 248 B | ||
| SNOVA | NIST candidate | 1 | 1,016 B | 48 B | 248 B | ||
| SNOVA | NIST candidate | 1 | 1,016 B | 36,848 B | 248 B | ||
| SNOVA | NIST candidate | 1 | 1,016 B | 36,848 B | 248 B | ||
| NTRU | Not selected by NIST | 3 | 1,138 B | 1,450 B | 1,138 B | ||
| Streamlined NTRU Prime | Not selected by NIST | 3 | 1,158 B | 1,763 B | 1,039 B | ||
| CRYSTALS-Kyber | Superseded | 3 | 1,184 B | 2,400 B | 1,088 B | ||
| ML-KEM | NIST standard | 3 | 1,184 B | 2,400 B | 1,088 B | ||
| NTRU | Not selected by NIST | 5 | 1,230 B | 1,590 B | 1,230 B | ||
| ML-DSA | NIST standard | 2 | 1,312 B | 2,560 B | 2,420 B | ||
| MAYO | NIST candidate | 1 | 1,420 B | 24 B | 454 B | ||
| CRYSTALS-Kyber | Superseded | 5 | 1,568 B | 3,168 B | 1,568 B | ||
| ML-KEM | NIST standard | 5 | 1,568 B | 3,168 B | 1,568 B | ||
| SNOVA | NIST candidate | 1 | 1,579 B | 48 B | 379 B | ||
| Falcon | Selected by NIST, standard in preparation | 5 | 1,793 B | 2,305 B | ≤ 1,462 B | ||
| Falcon | Selected by NIST, standard in preparation | 5 | 1,793 B | 2,305 B | 1,280 B | ||
| NTRU | Not selected by NIST | 5 | 1,842 B | 2,366 B | 1,842 B | ||
| ML-DSA | NIST standard | 3 | 1,952 B | 4,032 B | 3,309 B | ||
| HQC | Selected by NIST, standard in preparation | 1 | 2,249 B | 2,305 B | 4,433 B | ||
| SNOVA | NIST candidate | 1 | 2,320 B | 48 B | 165 B | ||
| NTRU | Not selected by NIST | 5 | 2,401 B | 2,983 B | 2,401 B | ||
| ML-DSA | NIST standard | 5 | 2,592 B | 4,896 B | 4,627 B | ||
| SNOVA | NIST candidate | 3 | 2,716 B | 48 B | 454 B | ||
| MAYO | NIST candidate | 3 | 2,986 B | 32 B | 681 B | ||
| SNOVA | NIST candidate | 3 | 4,112 B | 48 B | 376 B | ||
| HQC | Selected by NIST, standard in preparation | 3 | 4,522 B | 4,586 B | 8,978 B | ||
| MAYO | NIST candidate | 1 | 4,912 B | 24 B | 186 B | ||
| MAYO | NIST candidate | 5 | 5,554 B | 40 B | 964 B | ||
| SNOVA | NIST candidate | 5 | 6,006 B | 48 B | 286 B | ||
| HQC | Selected by NIST, standard in preparation | 5 | 7,245 B | 7,317 B | 14,421 B | ||
| SNOVA | NIST candidate | 5 | 8,016 B | 48 B | 576 B | ||
| FrodoKEM | Not selected by NIST | 1 | 9,616 B | 19,888 B | 9,752 B | ||
| FrodoKEM | Not selected by NIST | 1 | 9,616 B | 19,888 B | 9,752 B | ||
| eFrodoKEM | Not selected by NIST | 1 | 9,616 B | 19,888 B | 9,720 B | ||
| eFrodoKEM | Not selected by NIST | 1 | 9,616 B | 19,888 B | 9,720 B | ||
| SNOVA | NIST candidate | 3 | 9,842 B | 48 B | 124 B | ||
| FrodoKEM | Not selected by NIST | 3 | 15,632 B | 31,296 B | 15,792 B | ||
| FrodoKEM | Not selected by NIST | 3 | 15,632 B | 31,296 B | 15,792 B | ||
| eFrodoKEM | Not selected by NIST | 3 | 15,632 B | 31,296 B | 15,744 B | ||
| eFrodoKEM | Not selected by NIST | 3 | 15,632 B | 31,296 B | 15,744 B | ||
| FrodoKEM | Not selected by NIST | 5 | 21,520 B | 43,088 B | 21,696 B | ||
| FrodoKEM | Not selected by NIST | 5 | 21,520 B | 43,088 B | 21,696 B | ||
| eFrodoKEM | Not selected by NIST | 5 | 21,520 B | 43,088 B | 21,632 B | ||
| eFrodoKEM | Not selected by NIST | 5 | 21,520 B | 43,088 B | 21,632 B | ||
| SNOVA | NIST candidate | 5 | 31,266 B | 48 B | 178 B | ||
| UOV | NIST candidate | 1 | 43,576 B | 237,896 B | 128 B | ||
| UOV | NIST candidate | 1 | 43,576 B | 32 B | 128 B | ||
| UOV | NIST candidate | 1 | 66,576 B | 348,704 B | 96 B | ||
| UOV | NIST candidate | 1 | 66,576 B | 32 B | 96 B | ||
| UOV | NIST candidate | 3 | 189,232 B | 1,044,320 B | 200 B | ||
| UOV | NIST candidate | 3 | 189,232 B | 32 B | 200 B | ||
| Classic McEliece | Not selected by NIST | 1 | 261,120 B | 6,492 B | 96 B | ||
| Classic McEliece | Not selected by NIST | 1 | 261,120 B | 6,492 B | 96 B | ||
| UOV | NIST candidate | 1 | 278,432 B | 237,896 B | 128 B | ||
| UOV | NIST candidate | 1 | 412,160 B | 348,704 B | 96 B | ||
| UOV | NIST candidate | 5 | 446,992 B | 2,436,704 B | 260 B | ||
| UOV | NIST candidate | 5 | 446,992 B | 32 B | 260 B | ||
| Classic McEliece | Not selected by NIST | 3 | 524,160 B | 13,608 B | 156 B | ||
| Classic McEliece | Not selected by NIST | 3 | 524,160 B | 13,608 B | 156 B | ||
| Classic McEliece | Not selected by NIST | 5 | 1,044,992 B | 13,932 B | 208 B | ||
| Classic McEliece | Not selected by NIST | 5 | 1,044,992 B | 13,932 B | 208 B | ||
| Classic McEliece | Not selected by NIST | 5 | 1,047,319 B | 13,948 B | 194 B | ||
| Classic McEliece | Not selected by NIST | 5 | 1,047,319 B | 13,948 B | 194 B | ||
| UOV | NIST candidate | 3 | 1,225,440 B | 1,044,320 B | 200 B | ||
| Classic McEliece | Not selected by NIST | 5 | 1,357,824 B | 14,120 B | 208 B | ||
| Classic McEliece | Not selected by NIST | 5 | 1,357,824 B | 14,120 B | 208 B | ||
| UOV | NIST candidate | 5 | 2,869,440 B | 2,436,704 B | 260 B |
What is in the zoo
The zoo lists every key encapsulation mechanism and signature scheme of
liboqs 0.15.1, the C library of the Open Quantum Safe project, as packaged for the web by
@oqs/liboqs-js: 103 parameter sets in 15 families. For each one you see the sizes that decide whether it fits
a protocol — public key, private key, signature or ciphertext — its NIST security level, the hard problem it
rests on, and how far it has come in standardization. Pick any of them and the lab measures it on your own device
against the classical algorithm it would replace.
Where each family stands
The status column follows NIST's post-quantum project as of 20 October 2026:
- Standards. ML-KEM (FIPS 203), ML-DSA (FIPS 204) and SLH-DSA (FIPS 205), final since August 2024. These are the algorithms to deploy, and the ones TLS, X.509, JOSE and HPKE now define.
- Selected, standard in preparation. Falcon, which NIST is turning into FN-DSA (FIPS 206, not final yet; liboqs still ships round-3 Falcon, which FN-DSA will not match byte for byte), and HQC, the code-based KEM NIST picked in March 2025 (NIST IR 8545) as a backup resting on a different problem than ML-KEM.
- Candidates. MAYO, UOV, SNOVA and CROSS are in NIST's process for additional signatures, which looks for schemes with short signatures or assumptions other than lattices. None is a standard; their parameters may still change.
- Not selected. Classic McEliece, FrodoKEM, NTRU and Streamlined NTRU Prime were evaluated and not
chosen by NIST. That is not a verdict of insecurity: Germany's BSI recommends FrodoKEM and Classic McEliece for
conservative deployments, both are part of an ISO/IEC 18033-2 amendment, and OpenSSH used
sntrup761x25519-sha512before it moved to ML-KEM. - Superseded. CRYSTALS-Kyber as submitted to round 3. FIPS 203 changed it, so Kyber and ML-KEM do not interoperate; liboqs keeps it for existing deployments.
Sizes first
For most systems the bytes matter more than the microseconds. A TLS handshake with X25519MLKEM768 carries 2,336 bytes for the key exchange instead of 64; an ML-DSA-65 signature is 3,309 bytes against 64 for Ed25519. The families spread over four orders of magnitude: UOV signatures start at 96 bytes, with public keys of up to 2.8 MB, Classic McEliece ciphertexts are under 210 bytes with public keys of up to 1.3 MB, and SLH-DSA keys are 32 to 64 bytes with signatures of up to 49,856. The table's last column puts public key plus signature or ciphertext on a logarithmic scale, the only one on which all of them fit. Sort by it to find the smallest exchange of each kind.
How the benchmark measures
Measuring downloads one liboqs module from this site — JavaScript with the WebAssembly embedded, about 18 to 55 KB
when compressed — and runs it in a Web Worker, so the page stays responsive even while Classic McEliece generates a
megabyte-sized key. For each operation the runner first calibrates a batch: how many operations it takes to
last at least 5 milliseconds, because browsers coarsen performance.now() to 0.1 ms on pages that are not
cross-origin isolated. It then times eleven batches and reports the median per operation, within a budget of
three seconds per operation, so the slowest sets report fewer samples and say so.
Every result is checked while it is measured: each signature must verify, a tampered signature must not, and each decapsulation must recover the encapsulated secret. A miscompiled module cannot report a fast but wrong number. The sizes the module produces are compared with the registry too.
The classical baselines run the same way, through WebCrypto (the browser's native implementation) or through
the @noble/curves JavaScript library: ECDSA P-256 and Ed25519 for signatures, X25519 for key
encapsulation, used as a KEM by sending a fresh ephemeral public key. Where the browser's WebCrypto lacks Ed25519
or X25519, the JavaScript version stands in and the page says so.
What stays local
The zoo takes no input of yours: keys are generated inside the worker for the measurement and discarded. The modules come from this site, and neither your device's details nor the results are sent anywhere. A share link records only the selected algorithm and the filters.
From the zoo to the standards
To use the standardized algorithms rather than time them, the post-quantum signature lab signs and verifies ML-DSA, SLH-DSA and Falcon with every FIPS option, and the ML-KEM lab runs the TLS hybrids. FN-DSA vs ML-DSA and ML-DSA vs SLH-DSA weigh the signature families against each other, and Post-quantum migration in 2026 explains which deadlines apply.