Polyfill.io

Usage and performance

The public instance of the polyfill service is hosted by the Financial Times, with the generous support of Fastly, who provide CDN distribution. View Fastly network map

Traffic volume

This shows the number of requests we have served per day, over the last 180 days, measured by Fastly:

DateRequests
26 Oct 2016 00:0030140887
27 Oct 2016 00:0027209311
28 Oct 2016 00:0022178026
29 Oct 2016 00:0019129258
30 Oct 2016 00:0021318060
31 Oct 2016 00:0023299931
1 Nov 2016 00:0024402896
2 Nov 2016 00:0026355258
3 Nov 2016 00:0025909551
4 Nov 2016 00:0023480946
5 Nov 2016 00:0020199931
6 Nov 2016 00:0022447545
7 Nov 2016 00:0028036560
8 Nov 2016 00:0030319676
9 Nov 2016 00:0035729277
10 Nov 2016 00:0028236920
11 Nov 2016 00:0023899624
12 Nov 2016 00:0020133392
13 Nov 2016 00:0022264924
14 Nov 2016 00:0027186467
15 Nov 2016 00:0030446593
16 Nov 2016 00:0030784832
17 Nov 2016 00:0029370094
18 Nov 2016 00:0026674972
19 Nov 2016 00:0022262511
20 Nov 2016 00:0025073502
21 Nov 2016 00:0031263002
22 Nov 2016 00:0030925019
23 Nov 2016 00:0029816114
24 Nov 2016 00:0027293499
25 Nov 2016 00:0026902168
26 Nov 2016 00:0022597621
27 Nov 2016 00:0024901236
28 Nov 2016 00:0032238266
29 Nov 2016 00:0031756367
30 Nov 2016 00:0031972402
1 Dec 2016 00:0030561717
2 Dec 2016 00:0025721499
3 Dec 2016 00:0022570148
4 Dec 2016 00:0023583934
5 Dec 2016 00:0029746317
6 Dec 2016 00:0028589146
7 Dec 2016 00:0028071204
8 Dec 2016 00:0027172091
9 Dec 2016 00:0025654051
10 Dec 2016 00:0023840512
11 Dec 2016 00:0027162970
12 Dec 2016 00:0029199457
13 Dec 2016 00:0030700233
14 Dec 2016 00:0028966255
15 Dec 2016 00:0027179634
16 Dec 2016 00:0023121747
17 Dec 2016 00:0019178732
18 Dec 2016 00:0020423247
19 Dec 2016 00:0025638517
20 Dec 2016 00:0030054247
21 Dec 2016 00:0027293125
22 Dec 2016 00:0028253934
23 Dec 2016 00:0025218199
24 Dec 2016 00:0020462590
25 Dec 2016 00:0019624526
26 Dec 2016 00:0025538280
27 Dec 2016 00:0028313547
28 Dec 2016 00:0027086156
29 Dec 2016 00:0026405218
30 Dec 2016 00:0024943598
31 Dec 2016 00:0021225557
1 Jan 2017 00:0020654814
2 Jan 2017 00:0025885081
3 Jan 2017 00:0029892864
4 Jan 2017 00:0030166919
5 Jan 2017 00:0030594723
6 Jan 2017 00:0029425708
7 Jan 2017 00:0025402726
8 Jan 2017 00:0025982172
9 Jan 2017 00:0032314246
10 Jan 2017 00:0031809252
11 Jan 2017 00:0032536835
12 Jan 2017 00:0032799886
13 Jan 2017 00:0029391192
14 Jan 2017 00:0025300299
15 Jan 2017 00:0027282852
16 Jan 2017 00:0032524907
17 Jan 2017 00:0032415786
18 Jan 2017 00:0033365658
19 Jan 2017 00:0035120602
20 Jan 2017 00:0041188974
21 Jan 2017 00:0030927077
22 Jan 2017 00:0029338687
23 Jan 2017 00:0034284932
24 Jan 2017 00:0034671031
25 Jan 2017 00:0035619948
26 Jan 2017 00:0036071213
27 Jan 2017 00:0032465983
28 Jan 2017 00:0026966448
29 Jan 2017 00:0029740069
30 Jan 2017 00:0036063509
31 Jan 2017 00:0036152486
1 Feb 2017 00:0038016618
2 Feb 2017 00:0038092744
3 Feb 2017 00:0036796339
4 Feb 2017 00:0032491273
5 Feb 2017 00:0032453018
6 Feb 2017 00:0036860319
7 Feb 2017 00:0035571731
8 Feb 2017 00:0036412197
9 Feb 2017 00:0036514897
10 Feb 2017 00:0033490604
11 Feb 2017 00:0027995607
12 Feb 2017 00:0029223036
13 Feb 2017 00:0036885381
14 Feb 2017 00:0035887992
15 Feb 2017 00:0038363219
16 Feb 2017 00:0038642420
17 Feb 2017 00:0034407156
18 Feb 2017 00:0028874822
19 Feb 2017 00:0030971428
20 Feb 2017 00:0037275115
21 Feb 2017 00:0038420294
22 Feb 2017 00:0037623473
23 Feb 2017 00:0039089757
24 Feb 2017 00:0036219130
25 Feb 2017 00:0034519605
26 Feb 2017 00:0035891521
27 Feb 2017 00:0043712007
28 Feb 2017 00:0045064797
1 Mar 2017 00:0045392374
2 Mar 2017 00:0046631873
3 Mar 2017 00:0042165614
4 Mar 2017 00:0037713394
5 Mar 2017 00:0039805594
6 Mar 2017 00:0046066982
7 Mar 2017 00:0045176879
8 Mar 2017 00:0044774385
9 Mar 2017 00:0047826146
10 Mar 2017 00:0045210137
11 Mar 2017 00:0037960796
12 Mar 2017 00:0038080093
13 Mar 2017 00:0044997769
14 Mar 2017 00:0044341787
15 Mar 2017 00:0045435363
16 Mar 2017 00:0046967559
17 Mar 2017 00:0043404160
18 Mar 2017 00:0038636175
19 Mar 2017 00:0040990946
20 Mar 2017 00:0046873678
21 Mar 2017 00:0046191872
22 Mar 2017 00:0054879586
23 Mar 2017 00:0051247835
24 Mar 2017 00:0043630492
25 Mar 2017 00:0037657863
26 Mar 2017 00:0038374304
27 Mar 2017 00:0046018476
28 Mar 2017 00:0047087794
29 Mar 2017 00:0050447958
30 Mar 2017 00:0051112994
31 Mar 2017 00:0047293919
1 Apr 2017 00:0041000670
2 Apr 2017 00:0043531550
3 Apr 2017 00:0051512891
4 Apr 2017 00:0051372073
5 Apr 2017 00:0054481975
6 Apr 2017 00:0056145273
7 Apr 2017 00:0052098787
8 Apr 2017 00:0043880878
9 Apr 2017 00:0045799887
10 Apr 2017 00:0053918800
11 Apr 2017 00:0052654208
12 Apr 2017 00:0052502250
13 Apr 2017 00:0054089240
14 Apr 2017 00:0046311543
15 Apr 2017 00:0041134631
16 Apr 2017 00:0041256184
17 Apr 2017 00:0049758481
18 Apr 2017 00:0052956422
19 Apr 2017 00:0062803694
20 Apr 2017 00:0057519252
21 Apr 2017 00:0052213352
22 Apr 2017 00:0044706951
23 Apr 2017 00:0046211183

Response time

Mean global response time, ms, from Pingdom:

DateResponse time (ms)
17 Apr 2017 05:00360
17 Apr 2017 06:00364
17 Apr 2017 07:00350
17 Apr 2017 08:00356
17 Apr 2017 09:00344
17 Apr 2017 10:00356
17 Apr 2017 11:00345
17 Apr 2017 12:00353
17 Apr 2017 13:00368
17 Apr 2017 14:00352
17 Apr 2017 15:00343
17 Apr 2017 16:00347
17 Apr 2017 17:00368
17 Apr 2017 18:00366
17 Apr 2017 19:00367
17 Apr 2017 20:00347
17 Apr 2017 21:00355
17 Apr 2017 22:00359
17 Apr 2017 23:00350
18 Apr 2017 00:00345
18 Apr 2017 01:00343
18 Apr 2017 02:00353
18 Apr 2017 03:00345
18 Apr 2017 04:00345
18 Apr 2017 05:00342
18 Apr 2017 06:00339
18 Apr 2017 07:00345
18 Apr 2017 08:00341
18 Apr 2017 09:00342
18 Apr 2017 10:00350
18 Apr 2017 11:00467
18 Apr 2017 12:00345
18 Apr 2017 13:00348
18 Apr 2017 14:00346
18 Apr 2017 15:00357
18 Apr 2017 16:00351
18 Apr 2017 17:00369
18 Apr 2017 18:00354
18 Apr 2017 19:00349
18 Apr 2017 20:00365
18 Apr 2017 21:00346
18 Apr 2017 22:00350
18 Apr 2017 23:00344
19 Apr 2017 00:00341
19 Apr 2017 01:00339
19 Apr 2017 02:00345
19 Apr 2017 03:00361
19 Apr 2017 04:00341
19 Apr 2017 05:00345
19 Apr 2017 06:00370
19 Apr 2017 07:00347
19 Apr 2017 08:00348
19 Apr 2017 09:00351
19 Apr 2017 10:00374
19 Apr 2017 11:00346
19 Apr 2017 12:00344
19 Apr 2017 13:00355
19 Apr 2017 14:00355
19 Apr 2017 15:00341
19 Apr 2017 16:00329
19 Apr 2017 17:00327
19 Apr 2017 18:00331
19 Apr 2017 19:00353
19 Apr 2017 20:00341
19 Apr 2017 21:00336
19 Apr 2017 22:00329
19 Apr 2017 23:00324
20 Apr 2017 00:00334
20 Apr 2017 01:00335
20 Apr 2017 02:00326
20 Apr 2017 03:00320
20 Apr 2017 04:00322
20 Apr 2017 05:00333
20 Apr 2017 06:00322
20 Apr 2017 07:00323
20 Apr 2017 08:00334
20 Apr 2017 09:00310
20 Apr 2017 10:00302
20 Apr 2017 11:00310
20 Apr 2017 12:00300
20 Apr 2017 13:00317
20 Apr 2017 14:00319
20 Apr 2017 15:00328
20 Apr 2017 16:00317
20 Apr 2017 17:00309
20 Apr 2017 18:00363
20 Apr 2017 19:00343
20 Apr 2017 20:00314
20 Apr 2017 21:00312
20 Apr 2017 22:00305
20 Apr 2017 23:00311
21 Apr 2017 00:00321
21 Apr 2017 01:00318
21 Apr 2017 02:00315
21 Apr 2017 03:00311
21 Apr 2017 04:00326
21 Apr 2017 05:00315
21 Apr 2017 06:00322
21 Apr 2017 07:00310
21 Apr 2017 08:00321
21 Apr 2017 09:00313
21 Apr 2017 10:00313
21 Apr 2017 11:00313
21 Apr 2017 12:00328
21 Apr 2017 13:00317
21 Apr 2017 14:00346
21 Apr 2017 15:00350
21 Apr 2017 16:00312
21 Apr 2017 17:00332
21 Apr 2017 18:00312
21 Apr 2017 19:00306
21 Apr 2017 20:00323
21 Apr 2017 21:00339
21 Apr 2017 22:00315
21 Apr 2017 23:00317
22 Apr 2017 00:00314
22 Apr 2017 01:00321
22 Apr 2017 02:00316
22 Apr 2017 03:00305
22 Apr 2017 04:00318
22 Apr 2017 05:00304
22 Apr 2017 06:00330
22 Apr 2017 07:00346
22 Apr 2017 08:00357
22 Apr 2017 09:00338
22 Apr 2017 10:00343
22 Apr 2017 11:00337
22 Apr 2017 12:00339
22 Apr 2017 13:00346
22 Apr 2017 14:00346
22 Apr 2017 15:00349
22 Apr 2017 16:00356
22 Apr 2017 17:00351
22 Apr 2017 18:00352
22 Apr 2017 19:00349
22 Apr 2017 20:00351
22 Apr 2017 21:00335
22 Apr 2017 22:00355
22 Apr 2017 23:00358
23 Apr 2017 00:00340
23 Apr 2017 01:00337
23 Apr 2017 02:00335
23 Apr 2017 03:00333
23 Apr 2017 04:00333
23 Apr 2017 05:00347
23 Apr 2017 06:00359
23 Apr 2017 07:00369
23 Apr 2017 08:00343
23 Apr 2017 09:00328
23 Apr 2017 10:00334
23 Apr 2017 11:00365
23 Apr 2017 12:00337
23 Apr 2017 13:00337
23 Apr 2017 14:00334
23 Apr 2017 15:00346
23 Apr 2017 16:00340
23 Apr 2017 17:00346
23 Apr 2017 18:00333
23 Apr 2017 19:00343
23 Apr 2017 20:00337
23 Apr 2017 21:00334
23 Apr 2017 22:00336
23 Apr 2017 23:00341
24 Apr 2017 00:00361
24 Apr 2017 01:00327
24 Apr 2017 02:00334
24 Apr 2017 03:00331
24 Apr 2017 04:00331
24 Apr 2017 05:00327

Caching

Hit ratio, last 7 days, from Fastly:

Cache resultRequests
Hits5698282548
Misses322240325

Availability

Total downtime, according to Pingdom:

Last 30 daysNone
Last 3 months18 minutes
Last 12 monthsan hour

Caching responses that vary by User-Agent is very hard to do with good cache performance. We use a custom Fastly VCL configuration that separates the UA normalisation from the polyfill bundle.

Network performance in detail

95th percentile and median resource timing metrics, broken down by Fastly edge point of presence, measured using the resource timing API from live polyfill service requests that opted in to anonymously report performance data. Last 30 days, showing only POPs that have served more than 10000 RUM-enabled requests.

PoP Sample Per connection phase (95th percentile and median) Overall
LHR 62,504
617ms
(66ms)
IAD 25,957
760ms
(81ms)
DFW 20,470
835ms
(76ms)
HHN 19,726
841ms
(90ms)
LCY 12,968
616ms
(65ms)
AMS 11,189
671ms
(68ms)
ORD 10,760
946ms
(78ms)

Only non-zero samples are counted, which in practice means there are far fewer DNS lookup and TCP connect datapoints, because if reusing a keep-alive connection, both will be zero. Timings for individual connection phases do not sum to the overall RTT because, for example, the request that exhibits the 95th percentile DNS time, will most likely not also be the 95th percentile on all other connection metrics.

Typically Polyfill.io is loaded at a point where the browser is very busy. To speed up loading, consider using preconnect or preload.